Dell EMC PowerVault MD Series Service manual

Dell EMC PowerVault MD 34XX/38XX Series
Storage Arrays
Administrator's Guide

Notes, cautions, and warnings
NOTE: A NOTE indicates important information that helps you make better use of your product.
CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the problem.
WARNING: A WARNING indicates a potential for property damage, personal injury, or death.
© 2012 - 2018 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other
trademarks may be trademarks of their respective owners.
2018 - 05
Rev. A05

Contents
1 Introduction.................................................................................................................................................. 12
Dell EMC PowerVault Modular Disk Storage Manager................................................................................................ 12
User interface....................................................................................................................................................................12
Enterprise management window.................................................................................................................................... 13
Inheriting the system settings...................................................................................................................................13
Array management window.............................................................................................................................................14
Dell EMC PowerVault Modular Disk Conguration Utility........................................................................................... 15
Related documentation....................................................................................................................................................15
2 About your MD Series storage array.............................................................................................................16
Physical disks, virtual disks, and disk groups.................................................................................................................16
Physical disks.............................................................................................................................................................. 16
Physical disk states.....................................................................................................................................................16
Virtual disks and disk groups..................................................................................................................................... 17
Virtual disk states........................................................................................................................................................17
Disk pools...........................................................................................................................................................................18
Thin virtual disks............................................................................................................................................................... 18
RAID levels.........................................................................................................................................................................18
Maximum physical disk support limitations..............................................................................................................18
RAID level usage......................................................................................................................................................... 18
RAID 0..........................................................................................................................................................................19
RAID 1...........................................................................................................................................................................19
RAID 5..........................................................................................................................................................................19
RAID 6..........................................................................................................................................................................19
RAID 10.........................................................................................................................................................................19
Segment size.....................................................................................................................................................................19
Virtual disk operations..................................................................................................................................................... 20
Virtual disk initialization............................................................................................................................................. 20
Consistency check.....................................................................................................................................................20
Media verication.......................................................................................................................................................20
Cycle time................................................................................................................................................................... 20
Virtual disk operations limit........................................................................................................................................21
Disk group operations.......................................................................................................................................................21
RAID level migration................................................................................................................................................... 21
Segment size migration..............................................................................................................................................21
Virtual disk capacity expansion................................................................................................................................. 21
Disk group expansion.................................................................................................................................................22
Disk group defragmentation..................................................................................................................................... 22
Disk group operations limit........................................................................................................................................22
RAID background operations priority.............................................................................................................................22
Virtual disk migration and disk roaming......................................................................................................................... 23
Contents 3

Disk migration............................................................................................................................................................. 23
Disk roaming............................................................................................................................................................... 24
Host server-to-virtual disk mapping........................................................................................................................ 24
Host types...................................................................................................................................................................24
Advanced features........................................................................................................................................................... 24
Types of snapshot functionality supported.............................................................................................................25
Virtual disk copy.........................................................................................................................................................25
Virtual disk recovery.................................................................................................................................................. 26
Multi-path software.........................................................................................................................................................26
Preferred and alternate controllers and paths........................................................................................................26
Virtual disk ownership................................................................................................................................................26
Load balancing.................................................................................................................................................................. 27
Monitoring system performance.................................................................................................................................... 27
Interpreting performance monitor data...................................................................................................................28
Viewing real-time graphical performance monitor data........................................................................................ 30
Customizing the performance monitor dashboard.................................................................................................31
Specifying performance metrics...............................................................................................................................31
Viewing real-time textual performance monitor.....................................................................................................32
Saving real-time textual performance data.............................................................................................................33
Starting and stopping background performance monitor.....................................................................................33
Viewing information about the current background performance monitor session.......................................... 34
Viewing current background performance monitor data...................................................................................... 34
Saving the current background performance monitor data................................................................................. 35
Viewing saved background performance monitor data.........................................................................................35
Invalid objects in Performance Monitor...................................................................................................................36
3 Discovering and managing your storage array.............................................................................................. 37
Out-of-band management.............................................................................................................................................. 37
In-band management...................................................................................................................................................... 38
Access virtual disk......................................................................................................................................................38
Storage arrays.................................................................................................................................................................. 38
Automatic discovery of storage arrays....................................................................................................................38
Manual addition of storage array..............................................................................................................................38
Setting up your storage array.........................................................................................................................................39
Locating storage arrays.............................................................................................................................................40
Naming or renaming storage arrays.........................................................................................................................40
Setting a password....................................................................................................................................................40
Adding or editing a comment to an existing storage array.................................................................................... 41
Removing storage arrays...........................................................................................................................................42
Enabling premium features....................................................................................................................................... 42
Displaying failover alert..............................................................................................................................................42
Changing the cache settings on the storage array................................................................................................43
Changing expansion enclosure ID numbers............................................................................................................ 43
Changing the enclosure order.................................................................................................................................. 43
Conguring alert notications........................................................................................................................................ 43
Conguring e-mail alerts........................................................................................................................................... 44
4Contents

Conguring SNMP alerts..........................................................................................................................................45
Battery settings................................................................................................................................................................47
Changing the battery settings..................................................................................................................................47
Setting the storage array RAID controller module clocks........................................................................................... 48
4 Using iSCSI..................................................................................................................................................49
Changing the iSCSI target authentication....................................................................................................................49
Entering mutual authentication permissions................................................................................................................ 50
Creating CHAP secrets...................................................................................................................................................50
Initiator CHAP secret................................................................................................................................................ 50
Target CHAP secret...................................................................................................................................................50
Valid characters for CHAP secrets.......................................................................................................................... 50
Changing the iSCSI target identication........................................................................................................................51
Changing iSCSI target discovery settings..................................................................................................................... 51
Conguring the iSCSI host ports...................................................................................................................................52
Advanced iSCSI host port settings................................................................................................................................52
Viewing or ending an iSCSI session...............................................................................................................................53
Viewing iSCSI statistics and setting baseline statistics...............................................................................................53
Edit, remove, or rename host topology.........................................................................................................................54
5 Event monitor..............................................................................................................................................55
Enabling or disabling event monitor...............................................................................................................................55
Windows..................................................................................................................................................................... 55
Linux............................................................................................................................................................................ 56
6 About your host........................................................................................................................................... 57
Conguring host access..................................................................................................................................................57
Using the Host Mappings tab.........................................................................................................................................57
Dening a host........................................................................................................................................................... 58
Removing host access.................................................................................................................................................... 59
Managing host groups.....................................................................................................................................................59
Creating a host group......................................................................................................................................................59
Adding a host to a host group..................................................................................................................................59
Removing a host from a host group........................................................................................................................60
Moving a host to a dierent host group................................................................................................................. 60
Removing a host group.............................................................................................................................................60
Host topology.............................................................................................................................................................60
Starting or stopping the Host Context Agent.........................................................................................................61
I/O data path protection..................................................................................................................................................61
Managing host port identiers....................................................................................................................................... 62
7 Disk groups, standard virtual disks, and thin virtual disks............................................................................. 63
Creating disk groups and virtual disks...........................................................................................................................63
Creating disk groups..................................................................................................................................................63
Locating disk group....................................................................................................................................................64
Creating standard virtual disks.................................................................................................................................65
Contents 5

Changing the virtual disk modication priority.......................................................................................................66
Changing virtual disk cache settings.......................................................................................................................66
Changing segment size of virtual disk..................................................................................................................... 67
Changing the I/O type.............................................................................................................................................. 68
Thin virtual disks.............................................................................................................................................................. 68
Advantages of thin virtual disks............................................................................................................................... 68
Physical vs virtual capacity an a thin virtual disk................................................................................................... 69
Thin virtual disk requirements and limitations.........................................................................................................69
Thin virtual disk attributes.........................................................................................................................................70
Thin virtual disk states...............................................................................................................................................70
Comparison—Types of virtual disks and copy services........................................................................................ 70
Rollback on thin virtual disks..................................................................................................................................... 71
Initializing a thin virtual disk....................................................................................................................................... 71
Changing a thin virtual disk to a standard virtual disk........................................................................................... 74
Utilizing unmapping for thin virtual disk...................................................................................................................74
Enabling unmap thin provisioning for thin virtual disk............................................................................................74
Choosing an appropriate physical disk type..................................................................................................................75
Physical disk security with self encrypting disk............................................................................................................75
Creating a security key..............................................................................................................................................76
Changing security key................................................................................................................................................77
Saving a security key................................................................................................................................................. 78
Validate security key.................................................................................................................................................. 79
Unlocking secure physical disks............................................................................................................................... 79
Erasing secure physical disks....................................................................................................................................79
Conguring hot spare physical disks..............................................................................................................................79
Hot spares and rebuild...............................................................................................................................................80
Global hot spares....................................................................................................................................................... 80
Hot spare operation....................................................................................................................................................81
Hot spare physical disk protection............................................................................................................................81
Physical disk security........................................................................................................................................................81
Enclosure loss protection................................................................................................................................................ 82
Drawer loss protection.................................................................................................................................................... 83
Host-to-virtual disk mapping.......................................................................................................................................... 83
Creating host-to-virtual disk mappings................................................................................................................... 84
Modifying and removing host-to-virtual disk mapping..........................................................................................85
Changing RAID controller ownership of the virtual disk....................................................................................... 85
Removing host-to-virtual disk mapping.................................................................................................................. 86
Changing the RAID controller module ownership of a disk group....................................................................... 86
Changing the RAID level of a disk group.................................................................................................................86
Removing a host-to-virtual disk mapping using Linux DMMP..............................................................................87
Restricted mappings........................................................................................................................................................88
Storage partitioning......................................................................................................................................................... 88
Disk group and virtual disk expansion............................................................................................................................89
Disk group expansion.................................................................................................................................................89
Virtual disk expansion................................................................................................................................................90
6Contents

Using free capacity....................................................................................................................................................90
Using uncongured capacity.................................................................................................................................... 90
Disk group migration.........................................................................................................................................................91
Export disk group........................................................................................................................................................91
Import disk group....................................................................................................................................................... 92
Storage array media scan................................................................................................................................................92
Changing media scan settings..................................................................................................................................93
Suspending media scan.............................................................................................................................................93
8 Disk pools and disk pool virtual disks............................................................................................................94
Dierence between disk groups and disk pools........................................................................................................... 95
Disk pool restrictions....................................................................................................................................................... 95
Creating a disk pool manually......................................................................................................................................... 95
Automatically managing uncongured capacity in disk pools.....................................................................................96
Locating physical disks in a disk pool............................................................................................................................. 97
Renaming a disk pool....................................................................................................................................................... 97
Conguring alert notications for a disk pool............................................................................................................... 97
Adding unassigned physical disks to a disk pool.......................................................................................................... 98
Conguring the preservation capacity of a disk pool.................................................................................................. 98
Changing the modication priority of a disk pool.........................................................................................................98
Changing the RAID controller module ownership of a disk pool................................................................................99
Checking data consistency.............................................................................................................................................99
Deleting disk pool........................................................................................................................................................... 100
Viewing storage array logical components and associated physical components ................................................. 101
Secure disk pools.............................................................................................................................................................101
Changing capacity on existing thin virtual disks.........................................................................................................102
Creating thin virtual disk from disk pool...................................................................................................................... 102
9 Using SSD cache........................................................................................................................................104
How SSD cache works..................................................................................................................................................104
Benets of SSD cache...................................................................................................................................................104
Choosing SSD cache parameters.................................................................................................................................105
SSD cache restrictions.................................................................................................................................................. 105
Creating an SSD cache..................................................................................................................................................105
Viewing physical components associated with an SSD cache................................................................................. 106
Locating physical disks in an SSD cache.....................................................................................................................106
Adding physical disks to an SSD cache....................................................................................................................... 106
Removing physical disks from an SSD cache..............................................................................................................107
Suspending or resuming SSD caching......................................................................................................................... 107
Changing I/O type in an SSD cache............................................................................................................................ 107
Renaming an SSD cache............................................................................................................................................... 107
Deleting SSD cache....................................................................................................................................................... 108
Using the performance modeling tool..........................................................................................................................108
10 Premium feature—Snapshot Virtual Disk..................................................................................................109
Snapshot images and groups........................................................................................................................................109
Contents 7

Snapshot Virtual Disk read/write properties...............................................................................................................109
Snapshot groups and consistency groups................................................................................................................... 110
Snapshot groups....................................................................................................................................................... 110
Snapshot consistency groups..................................................................................................................................110
Understanding snapshot repositories............................................................................................................................ 111
Consistency group repositories................................................................................................................................ 111
Ranking repository candidates..................................................................................................................................111
Using snapshot consistency group to a Remote Replication................................................................................111
Creating snapshot images..............................................................................................................................................112
Creating snapshot image..........................................................................................................................................112
Canceling a pending snapshot image......................................................................................................................113
Deleting snapshot image.......................................................................................................................................... 113
Scheduling snapshot images..........................................................................................................................................114
Creating a snapshot schedule..................................................................................................................................114
Editing a snapshot schedule.................................................................................................................................... 115
Performing snapshot rollbacks...................................................................................................................................... 115
Snapshot rollback limitations................................................................................................................................... 115
Starting snapshot rollback........................................................................................................................................116
Resuming a snapshot image rollback......................................................................................................................116
Canceling snapshot image rollback......................................................................................................................... 117
Viewing the progress of a snapshot rollback......................................................................................................... 117
Changing snapshot rollback priority........................................................................................................................ 117
Creating snapshot group................................................................................................................................................ 118
Manually creating a consistency group repository................................................................................................ 119
Changing snapshot group settings.........................................................................................................................120
Renaming a snapshot group....................................................................................................................................120
Deleting snapshot group...........................................................................................................................................121
Converting a snapshot Virtual Disk to read-write....................................................................................................... 121
Viewing associated physical components of an individual repository virtual disk................................................... 121
Creating consistency group...........................................................................................................................................122
Manually creating a consistency group repository................................................................................................123
Renaming a consistency group............................................................................................................................... 124
Deleting consistency group..................................................................................................................................... 124
Changing the settings of a consistency group......................................................................................................124
Adding a member virtual disk to a consistency group......................................................................................... 125
Removing member virtual disk from consistency group......................................................................................126
Creating a snapshot virtual disk of a snapshot image................................................................................................126
Snapshot Virtual Disk limitations.............................................................................................................................126
Creating Snapshot Virtual Disk............................................................................................................................... 127
Creating a Snapshot Virtual Disk repository..........................................................................................................128
Changing the settings of a Snapshot Virtual Disk................................................................................................129
Disabling Snapshot Virtual Disk or consistency group Snapshot Virtual Disk................................................... 129
Re-creating a Snapshot Virtual Disk or consistency group Snapshot Virtual Disk...........................................130
Renaming a Snapshot Virtual Disk or consistency group Snapshot Virtual Disk..............................................130
Creating consistency group Snapshot Virtual Disk..................................................................................................... 131
8Contents

Manually creating a consistency group Snapshot Virtual Disk repository......................................................... 132
Disabling Snapshot Virtual Disk or consistency group Snapshot Virtual Disk................................................... 133
Re-creating a Snapshot Virtual Disk or consistency group Snapshot Virtual Disk........................................... 134
Changing the modication priority of an overall repository virtual disk.............................................................135
Changing the media scan setting of an overall repository virtual disk...............................................................135
Changing the pre-read consistency check setting of an overall repository virtual disk...................................136
Increasing capacity of overall repository................................................................................................................137
Decreasing the capacity of the overall repository................................................................................................ 138
Performing revive operation....................................................................................................................................139
11 Premium feature—virtual disk copy...........................................................................................................140
Types of virtual disk copies............................................................................................................................................ 141
Oine copy................................................................................................................................................................141
Online copy................................................................................................................................................................ 141
Creating a virtual disk copy for an MSCS shared disk................................................................................................141
Virtual disk read/write permissions.............................................................................................................................. 142
Virtual disk copy restrictions......................................................................................................................................... 142
Creating a virtual disk copy........................................................................................................................................... 142
Setting read/write permissions on target virtual disk.......................................................................................... 143
Before you begin.......................................................................................................................................................143
Virtual disk copy and modication operations.......................................................................................................143
Create copy wizard...................................................................................................................................................143
Failed virtual disk copy.............................................................................................................................................144
Preferred RAID controller module ownership..............................................................................................................144
Failed RAID controller module.......................................................................................................................................144
Copy manager.................................................................................................................................................................144
Copying the virtual disk................................................................................................................................................. 144
Storage array performance during virtual disk copy.................................................................................................. 145
Setting copy priority.......................................................................................................................................................145
Stopping a virtual disk copy.......................................................................................................................................... 146
Recopying a virtual disk................................................................................................................................................. 146
Preparing host servers to recopy virtual disk........................................................................................................146
Recopying the virtual disk........................................................................................................................................147
Removing copy pairs...................................................................................................................................................... 147
12 Device Mapper multipath for Linux............................................................................................................148
Overview......................................................................................................................................................................... 148
Using Device Mapper Multipathing Devices (DMMP).............................................................................................. 148
Prerequisites..............................................................................................................................................................148
Device Mapper conguration steps............................................................................................................................. 149
Scan for newly added virtual disks.........................................................................................................................149
Display multipath device topology using multipath command............................................................................ 149
Create fdisk partition on multipath device node...................................................................................................150
Add new partition to Device Mapper.....................................................................................................................150
Create le system on Device Mapper partition..................................................................................................... 151
Mount a Device Mapper partition........................................................................................................................... 151
Contents 9

Ready for use.............................................................................................................................................................151
Linux host server reboot best practices.......................................................................................................................151
Important information about special partitions...........................................................................................................152
Limitations and known issues........................................................................................................................................152
Troubleshooting.............................................................................................................................................................. 153
13 Conguring Asymmetric Logical Unit Access............................................................................................ 154
ALUA performance considerations...............................................................................................................................154
Automatic transfer of ownership..................................................................................................................................154
Native ALUA support on Microsoft Windows and Linux........................................................................................... 154
Enabling ALUA on VMware ESXi .................................................................................................................................155
Manually adding SATP rule in ESXi 5.x..................................................................................................................155
Verifying ALUA on VMware ESXi................................................................................................................................. 155
Verifying if host server is using ALUA for MD storage array.................................................................................... 155
Setting round-robin load balancing policy on ESXi-based storage arrays............................................................... 156
14 Premium feature—Remote Replication..................................................................................................... 157
About asynchronous Remote Replication....................................................................................................................157
Remote replicated pairs and replication repositories.................................................................................................. 157
Types of Remote Replication........................................................................................................................................ 158
Dierences between Remote Replication features..............................................................................................158
Upgrading to asynchronous Remote Replication from Remote Replication (legacy)...................................... 158
Remote Replication requirements and restrictions.....................................................................................................159
Restrictions on using Remote Replication.............................................................................................................159
Setting up Remote Replication..................................................................................................................................... 159
Activating Remote Replication premium features...................................................................................................... 159
Deactivating Remote Replication................................................................................................................................. 160
Remote Replication groups........................................................................................................................................... 160
Purpose of a Remote Replication group................................................................................................................160
Remote Replication group requirements and guidelines.......................................................................................161
Creating a Remote Replication group..................................................................................................................... 161
Replicated pairs............................................................................................................................................................... 161
Guidelines for choosing virtual disks in a replicated pair.......................................................................................161
Guidelines for choosing virtual disks in a replicated pair......................................................................................162
Creating replicated pairs.......................................................................................................................................... 162
Removing replicated pair from Remote Replication group..................................................................................163
15 Management rmware downloads............................................................................................................ 164
Downloading RAID controller and NVSRAM packages............................................................................................. 164
Downloading both RAID controller and NVSRAM rmware..................................................................................... 164
Downloading only NVSRAM rmware......................................................................................................................... 165
Downloading physical disk rmware.............................................................................................................................167
Downloading MD3060e Series expansion module EMM rmware.......................................................................... 167
Self-Monitoring Analysis and Reporting Technology (SMART)................................................................................168
Media errors and unreadable sectors...........................................................................................................................168
10 Contents

16 Firmware inventory................................................................................................................................... 170
Viewing the rmware inventory....................................................................................................................................170
17 System interfaces...................................................................................................................................... 171
Virtual disk service.......................................................................................................................................................... 171
Volume shadow-copy service........................................................................................................................................ 171
18 Storage array software..............................................................................................................................173
Start-up routine.............................................................................................................................................................. 173
Device health conditions................................................................................................................................................173
Trace buers................................................................................................................................................................... 175
Retrieving trace buers........................................................................................................................................... 176
Collecting physical disk data..........................................................................................................................................176
Creating a support data collection schedule......................................................................................................... 176
Suspending or resuming a support data collection schedule.............................................................................. 177
Removing a support data collection schedule.......................................................................................................177
Event log.......................................................................................................................................................................... 177
Viewing the event log...............................................................................................................................................178
Recovery Guru................................................................................................................................................................ 178
Storage array prole....................................................................................................................................................... 178
Viewing the physical associations.................................................................................................................................179
Recovering from unresponsive storage array condition.............................................................................................179
Locating a physical disk.................................................................................................................................................. 181
Locating an expansion enclosure...................................................................................................................................181
Capturing state information.......................................................................................................................................... 182
SMrepassist utility.......................................................................................................................................................... 182
Unidentied devices.......................................................................................................................................................182
Recovering from unidentied storage array................................................................................................................183
Starting or restarting the Host Context Agent software.......................................................................................... 184
Starting the SMagent software in Windows.........................................................................................................184
Starting SMagent software in Linux...................................................................................................................... 184
19 Getting help..............................................................................................................................................185
Contacting Dell EMC..................................................................................................................................................... 185
Contents 11

Introduction
CAUTION: See the Safety, Environmental, and Regulatory Information document for important safety information before
following any procedures listed in this document.
The following MD Series systems are supported by the latest version of Dell PowerVault Modular Disk Manager (MDSM):
• 2U MD Series systems:
– Dell PowerVault MD 3400/3420
– Dell PowerVault MD 3800i/3820i
– Dell PowerVault MD 3800f/3820f
• 4U (dense) MD Series systems:
– Dell PowerVault MD 3460
– Dell PowerVault MD 3860i
– Dell PowerVault MD 3860f
NOTE: The Dell MD Series storage array supports up to 192 drives for the 2U arrays or 180 drives for the 4U (dense) arrays after
the installation of the Additional Physical Disk Support Premium Feature Key.
Topics:
• Dell EMC PowerVault Modular Disk Storage Manager
• User interface
• Enterprise management window
• Array management window
• Dell EMC PowerVault Modular Disk Conguration Utility
• Related documentation
Dell EMC PowerVault Modular Disk Storage Manager
Dell EMC PowerVault Modular Disk Storage Manager (MD Storage Manager) is a graphical user interface (GUI) application used to
congure and manage one or more MD Series storage arrays. The MD Storage Manager software is located on the MD Series resource
DVD.
For detailed information on installing the MD Storage Manager, see the storage array’s Deployment Guide at Dell.com/support/manuals.
User interface
The Storage Manager screen is divided into two primary windows:
• Enterprise Management Window (EMW)—The EMW provides high-level management of multiple storage arrays. You can launch the
Array Management Windows for the storage arrays from the EMW.
• Array Management Window (AMW)—The AMW provides management functions for a single storage array.
The EMW and the AMW consist of the following:
• The title bar at the top of the window—Shows the name of the application.
1
12 Introduction

• The menu bar, beneath the title bar—You can select menu options from the menu bar to perform tasks on a storage array.
• The toolbar, beneath the menu bar—You can select options in the toolbar to perform tasks on a storage array.
NOTE: The toolbar is available only in the EMW.
• The tabs, beneath the toolbar—Tabs are used to group the tasks that you can perform on a storage array.
• The status bar, beneath the tabs—The status bar shows status messages and status icons related to the storage array.
NOTE: By default, the toolbar and status bar are not displayed. To view the toolbar or the status bar, select View > Toolbar or
View > Status Bar.
Enterprise management window
The EMW provides high-level management of storage arrays. When you start the MD Storage Manager, the EMW is displayed. The EMW
has the:
•Devices tab — Provides information about discovered storage arrays.
•Setup tab — Presents the initial setup tasks that guide you through adding storage arrays and conguring alerts.
The Devices tab has a Tree view on the left side of the window that shows discovered storage arrays, unidentied storage arrays, and the
status conditions for the storage arrays. Discovered storage arrays are managed by the MD Storage Manager. Unidentied storage arrays
are available to the MD Storage Manager but not congured for management. The right side of the Devices tab has a Table view that
shows detailed information for the selected storage array.
In the EMW, you can:
• Discover hosts and managed storage arrays on the local sub-network.
• Manually add and remove hosts and storage arrays.
• Blink or locate the storage arrays.
• Name or rename discovered storage arrays.
• Add comments for a storage array in the Table view.
• Schedule or automatically save a copy of the support data when the client monitor process detects an event.
• Store your EMW view preferences and conguration data in local conguration les. The next time you open the EMW, data from the
local conguration les is used to show customized view and preferences.
• Monitor the status of managed storage arrays and indicate status using appropriate icons.
• Add or remove management connections.
•Congure alert notications for all selected storage arrays through e-mail or SNMP traps.
• Report critical events to the congured alert destinations.
• Launch the AMW for a selected storage array.
• Run a script to perform batch management tasks on specic storage arrays.
• Import the operating system theme settings into the MD Storage Manager.
• Upgrade rmware on multiple storage arrays concurrently.
• Obtain information about the rmware inventory including the version of the RAID controller modules, physical disks, and the enclosure
management modules (EMMs) in the storage array.
Inheriting the system settings
Use the Inherit System Settings option to import the operating system theme settings into the MD Storage Manager. Importing system
theme settings aects the font type, font size, color, and contrast in the MD Storage Manager.
1 From the EMW, open the Inherit System Settings window in one of these ways:
• Select Tools > Inherit System Settings.
• Select the Setup tab, and under Accessibility, click Inherit System Settings.
2 Select Inherit system settings for color and font.
Introduction 13

3 Click OK.
Array management window
You can launch the AMW from the EMW. The AMW provides management functions for a single storage array. You can have multiple
AMWs open simultaneously to manage dierent storage arrays.
In the AMW, you can:
• Select storage array options — For example, renaming a storage array, changing a password, or enabling a background media scan.
•Congure virtual disks and disk pools from the storage array capacity, dene hosts and host groups, and grant host or host group
access to sets of virtual disks called storage partitions.
• Monitor the health of storage array components and report detailed status using applicable icons.
• Perform recovery procedures for a failed logical component or a failed hardware component.
• View the Event Log for a storage array.
• View prole information about hardware components, such as RAID controller modules and physical disks.
• Manage RAID controller modules — For example, changing ownership of virtual disks or placing a RAID controller module online or
oine.
• Manage physical disks — For example, assignment of hot spares and locating the physical disk.
• Monitor storage array performance.
To launch the AMW:
1 In the EMW, on the Devices tab, right-click on the relevant storage array.
The context menu for the selected storage is displayed.
2 In the context menu, select Manage Storage Array.
The AMW for the selected storage array is displayed.
NOTE: You can also launch the AMW by:
• Double-clicking on a storage array displayed in the Devices tab of the EMW.
• Selecting a storage array displayed in the Devices tab of the EMW, and then selecting Tools > Manage Storage Array.
The AMW has the following tabs:
•Summary tab — You can view the following information about the storage array:
– Status
– Hardware
– Storage and copy services
– Hosts and mappings
– Information about storage capacity
– Premium features
•Performance tab — You can track a storage array’s key performance data and identify performance bottlenecks in your system. You
can monitor the system performance in the following ways:
– Real-time graphical
– Real-time textual
– Background (historical)
•Storage & Copy Services tab — You can view and manage the organization of the storage array by virtual disks, disk groups, free
capacity nodes, and any uncongured capacity for the storage array.
•Host Mappings tab — You can dene the hosts, host groups, and host ports. You can change the mappings to grant virtual disk
access to host groups and hosts and create storage partitions.
•Hardware tab — You can view and manage the physical components of the storage array.
•Setup tab — Shows a list of initial setup tasks for the storage array.
14 Introduction

Dell EMC PowerVault Modular Disk Conguration
Utility
NOTE: Dell EMC PowerVault Modular Disk Conguration Utility (MDCU) is supported only on MD Series storage arrays that use
the iSCSI protocol.
MDCU is an iSCSI Conguration Wizard that can be used with MD Storage Manager to simplify the conguration of iSCSI connections.
The MDCU software is available on the MD Series resource media.
Related documentation
NOTE: For all Storage documentation, go to Dell.com/powervaultmanuals and enter the system Service Tag to get your system
documentation.
NOTE: For all Dell EMC OpenManage documents, go to Dell.com/openmanagemanuals.
NOTE: For all storage controller documents, go to Dell.com/storagecontrollermanuals.
Your product documentation includes:
•Dell EMC PowerVault MD3460/MD3860i/MD3860f Storage Arrays Getting Started Guide—Provides an overview of system features,
setting up your system, and technical specications. This document is also shipped with your system.
•Dell EMC PowerVault MD3460/MD3860i/MD3860f Storage Arrays Owner’s Manual—Provides information about system features
and describes troubleshooting the system and install or replace system components.
•Rack Installation Instructions—Describes installing your system into a rack. This document is also shipped with your rack solution.
•Dell EMC PowerVault MD Series Storage Arrays Administrator's Guide—Provides information about conguring and managing the
system by using the MDSM GUI.
•Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays CLI Guide—Provides information about conguring and managing the
system using the MDSM CLI.
•Dell EMC PowerVault MD3460/MD3860i/MD3860f Storage Arrays Deployment Guide—Provides information about deploying the
storage system in the SAN architecture.
•Dell EMC PowerVault MD 34xx and 38xx Series Support Matrix—Provides information about the software and hardware compatibility
matrices for the storage array.
Introduction 15

About your MD Series storage array
This chapter describes the storage array concepts, which help in conguring and operating the Dell MD Series storage arrays.
Physical disks, virtual disks, and disk groups
Physical disks in your storage array provide the physical storage capacity for your data. Before you can begin writing data to the storage
array, you must congure the physical storage capacity into logical components, called disk groups and virtual disks.
A disk group is a set of physical disks upon which multiple virtual disks are created. The maximum number of physical disks supported in a
disk group is:
• 96 disks for RAID 0, RAID 1, and RAID 10
• 30 disks for RAID 5 and RAID 6
You can create disk groups from uncongured capacity on your storage array.
A virtual disk is a partition in a disk group that is made up of contiguous data segments of the physical disks in the disk group. A virtual disk
consists of data segments from all physical disks in the disk group.
All virtual disks in a disk group support the same RAID level. The storage array supports up to 255 virtual disks (minimum size of 10 MB
each) that can be assigned to host servers. Each virtual disk is assigned a Logical Unit Number (LUN) that is recognized by the host
operating system.
Virtual disks and disk groups are set up according to how you plan to organize your data. For example, you can have one virtual disk for
inventory, a second virtual disk for nancial and tax information, and so on.
Physical disks
Only Dell EMC supported physical disks are supported in the storage array. If the storage array detects unsupported physical disks, it marks
the disk as unsupported and the physical disk becomes unavailable for all operations.
For the list of supported physical disks, see the Support Matrix at Dell.com/support/manuals.
Physical disk states
The following describes the various states of the physical disk, which are recognized by the storage array and reported in the MD Storage
Manager under the Hardware tab or in the Storage Array Prole on the Summary tab.
Table 1. Physical disk states
Status Mode Description
Optimal Assigned The physical disk in the indicated slot is congured as part of a
disk group.
Optimal Unassigned The physical disk in the indicated slot is unused and available to be
congured.
Optimal Hot Spare Standby The physical disk in the indicated slot is congured as a hot spare.
2
16 About your MD Series storage array

Status Mode Description
Optimal Hot Spare in use The physical disk in the indicated slot is in use as a hot spare
within a disk group.
Failed Assigned, Unassigned, Hot Spare in use,
or Hot Spare Standby
The physical disk in the indicated slot has failed because of an
unrecoverable error, an incorrect physical disk type or physical disk
size, or by its operational state being set to failed.
Replaced Assigned The physical disk in the indicated slot has been replaced and is
ready to be, or is actively being, congured into a disk group.
Pending Failure Assigned, Unassigned, Hot Spare in use,
or Hot Spare Standby
A Self-Monitoring Analysis and Reporting Technology (SMART)
error has been detected on the physical disk in the indicated slot.
Oine Not applicable The physical disk has either been spun down or had a rebuild
ended by user request.
Identify Assigned, Unassigned, Hot Spare in use,
or Hot Spare Standby
The physical disk is being identied.
Virtual disks and disk groups
When conguring a storage array, you must:
• Organize the physical disks into disk groups.
• Create virtual disks within these disk groups.
• Provide host server access.
• Create mappings to associate the virtual disks with the host servers.
NOTE: Host server access must be created before mapping virtual disks.
Disk groups are always created in the uncongured capacity of a storage array. Uncongured capacity is the available physical disk space
not already assigned in the storage array.
Virtual disks are created within the free capacity of a disk group. Free capacity is the space in a disk group that has not been assigned to a
virtual disk.
Virtual disk states
The following table describes the various states of the virtual disk, recognized by the storage array.
Table 2. Raid controller virtual disk states
State Description
Optimal The virtual disk contains physical disks that are online.
Degraded The virtual disk with a redundant RAID level contains an inaccessible
physical disk. The system can still function properly, but performance
may be aected and more disk failures may result in data loss.
Oine A virtual disk with one or more member disks in an inaccessible (failed,
missing, or oine) state. Data on the virtual disk is no longer accessible.
Force online The storage array forces a virtual disk that is in an Oine state to an
Optimal state. If all the member physical disks are not available, the
storage array forces the virtual disk to a Degraded state. The storage
About your MD Series storage array 17

State Description
array can force a virtual disk to an Online state only when enough of
physical disks are available to support the virtual disk.
Disk pools
Disk pooling allows you to distribute data from each virtual disk randomly across a set of physical disks. Although there is no limit on the
maximum number of physical disks that can comprise a disk pool, each disk pool must have a minimum of 11 physical disks. Additionally, the
disk pool cannot contain more physical disks than the maximum limit for each storage array.
Thin virtual disks
Thin virtual disks can be created from an existing disk pool. Creating thin virtual disks allows you to set up a large virtual space, but only use
the actual physical space as you need it.
RAID levels
RAID levels determine the way in which data is written to physical disks. Dierent RAID levels provide dierent levels of accessibility,
consistency, and capacity.
Using multiple physical disks has the following advantages over using a single physical disk:
• Placing data on multiple physical disks (striping) allows input/output (I/O) operations to occur simultaneously and improve
performance.
• Storing redundant data on multiple physical disks using replication or consistency supports reconstruction of lost data if an error occurs,
even if that error is the failure of a physical disk.
Each RAID level provides dierent performance and protection. You must select a RAID level based on the type of application, access, fault
tolerance, and data you are storing.
The storage array supports RAID levels 0, 1, 5, 6, and 10. The maximum and minimum number of physical disks that can be used in a disk
group depends on the RAID level:
• 120 (180 with PFK) for RAID 0, 1, and 10
• 30 for RAID 5 and 6
Maximum physical disk support limitations
Although PowerVault MD Series storage arrays with premium feature kit can support up to 180 physical disks, RAID 0 and RAID 10
congurations with more than 120 physical disks are not supported. MD Storage Manager does not enforce 120-physical disk limit when
you setup a RAID 0 or RAID 10 conguration. Exceeding the 120-physical disk limit may cause your storage array to be unstable.
RAID level usage
To ensure best performance, you must select an optimal RAID level when you create a system physical disk. The optimal RAID level for your
disk array depends on:
• Number of physical disks in the disk array
• Capacity of the physical disks in the disk array
• Need for redundant access to the data (fault tolerance)
• Disk performance requirements
18 About your MD Series storage array

RAID 0
CAUTION: Do not attempt to create virtual disk groups exceeding 120 physical disks in a RAID 0 conguration even if premium
feature is activated on your storage array. Exceeding the 120-physical disk limit may cause your storage array to be unstable.
RAID 0 uses disk striping to provide high data throughput, especially for large les in an environment that requires no data consistency.
RAID 0 breaks the data down into segments and writes each segment to a separate physical disk. I/O performance is greatly improved by
spreading the I/O load across many physical disks. Although it oers the best performance of any RAID level, RAID 0 lacks data
consistency. Choose this option only for non-critical data, because failure of one physical disk results in the loss of all data. Examples of
RAID 0 applications include video editing, image editing, prepress applications, or any application that requires high bandwidth.
RAID 1
RAID 1 uses disk replication so that data written to one physical disk is simultaneously written to another physical disk. RAID 1 oers fast
performance and the best data availability, but also the highest disk overhead. RAID 1 is recommended for small databases or other
applications that do not require large capacity. For example, accounting, payroll, or nancial applications. RAID 1 provides full data
consistency.
RAID 5
RAID 5 uses consistency and striping data across all physical disks (distributed consistency) to provide high data throughput and data
consistency, especially for small random access. RAID 5 is a versatile RAID level and is suited for multi-user environments where typical I/O
size is small and there is a high proportion of read activity such as le, application, database, web, e-mail, news, and intranet servers.
RAID 6
RAID 6 is similar to RAID 5 but provides an additional consistency disk for better consistency. RAID 6 is the most versatile RAID level and is
suited for multi-user environments where typical I/O size is small and there is a high proportion of read activity. RAID 6 is recommended
when large size physical disks are used or large number of physical disks are used in a disk group.
RAID 10
CAUTION: Do not attempt to create virtual disk groups exceeding 120 physical disks in a RAID 10 conguration even if premium
feature is activated on your storage array. Exceeding the 120-physical disk limit may cause your storage array to be unstable.
RAID 10, a combination of RAID 1 and RAID 0, uses disk striping across replicated disks. It provides high data throughput and complete data
consistency. Using an even number of physical disks (four or more) creates a RAID level 10 disk group and/or virtual disk. Because RAID
levels 1 and 10 use disk replication, half of the capacity of the physical disks is used for replication. This leaves the remaining half of the
physical disk capacity for actual storage. RAID 10 is automatically used when a RAID level of 1 is chosen with four or more physical disks.
RAID 10 works well for medium-sized databases or any environment that requires high performance and fault tolerance and moderate-to-
medium capacity.
Segment size
Disk striping enables data to be written across multiple physical disks. Disk striping enhances performance because striped disks are
accessed simultaneously.
About your MD Series storage array 19

The segment size or stripe element size species the size of data in a stripe written to a single disk. The storage array supports stripe
element sizes of 8 KB, 16 KB, 32 KB, 64 KB, 128 KB, and 256 KB. The default stripe element size is 128 KB.
Stripe width, or depth, refers to the number of disks involved in an array where striping is implemented. For example, a 4-disk group with
disk striping has a stripe width of four.
NOTE: Although disk striping delivers excellent performance, striping alone does not provide data consistency.
Virtual disk operations
Virtual disk initialization
Every virtual disk must be initialized. Initialization is done in the background automatically, however the priority can be modied by updating
the Change Modication Priority option. This change can aect the performance of the array until the initialization is complete. A maximum
of four virtual disks can be initialized concurrently on each RAID controller module.
The storage array executes a background initialization when the virtual disk is created to establish consistency, while allowing full host
server access to the virtual disks. Background initialization does not run on RAID 0 virtual disks. The background initialization rate is
controlled by MD Storage Manager. To change the rate of background initialization, you must stop any existing background initialization.
The rate change is implemented when the background initialization restarts automatically.
Consistency check
A consistency check veries the correctness of data in a redundant array—RAID levels 1, 5, 6, and 10. For example, in a system with parity,
checking consistency involves computing the data on one physical disk and comparing the results to the contents of the parity physical
disk.
A consistency check is similar to a background initialization. The dierence is that background initialization cannot be started or stopped
manually, while consistency check can.
NOTE: It is recommended that you run data consistency checks on a redundant array at least once a month. This data
consistency check allows detection and automatic replacement of unreadable sectors. Finding an unreadable sector during a
rebuild of a failed physical disk is a serious problem because the system does not have the consistency to recover the data.
Media verication
Another background task performed by the storage array is media verication of all congured physical disks in a disk group. The storage
array uses the Read operation to perform verication on the space congured in virtual disks and the space reserved for the metadata.
Cycle time
The media verication operation runs only on selected disk groups, independent of other disk groups. Cycle time is the time taken to
complete verication of the metadata region of the disk group and all virtual disks in the disk group for which media verication is
congured. The next cycle for a disk group starts automatically when the current cycle completes. You can set the cycle time for a media
verication operation between 1 and 30 days. The storage controller throttles the media verication I/O accesses to disks based on the
cycle time.
The storage array tracks the cycle for each disk group independent of other disk groups on the RAID controller and creates a checkpoint. If
the media verication operation on a disk group is preempted or blocked by another operation on the disk group, the storage array resumes
20 About your MD Series storage array