Dell EMC H745P MX User manual

Dell EMC PowerEdge RAID Controller 10 User’s
Guide
H740P, H745P MX, and H840
Regulatory Model: UCPA-1001, UCPB-1000, UCPE-1000 and UCPJ-1000

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.
© 2017 - 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 - 11
Rev. A03

Contents
1 Overview........................................................................................................................................................8
Supported operating systems...........................................................................................................................................8
PERC card specications..................................................................................................................................................9
Management applications for PERC cards.....................................................................................................................9
Comprehensive embedded management ...............................................................................................................10
Dell OpenManage Storage Management................................................................................................................ 10
Related documentation....................................................................................................................................................10
2 Getting Started.............................................................................................................................................11
3 Features....................................................................................................................................................... 13
Controller features............................................................................................................................................................13
FastPath.......................................................................................................................................................................13
Disk roaming................................................................................................................................................................ 13
1 MB IO.........................................................................................................................................................................14
Physical disk power management.............................................................................................................................14
Secure rmware update.............................................................................................................................................14
Enhanced HBA mode................................................................................................................................................. 14
Non-RAID disks...........................................................................................................................................................15
Auto Congure RAID 0...............................................................................................................................................15
PERC H745P MX enclosure support....................................................................................................................... 15
PERC H840 enclosure support................................................................................................................................. 17
Prole Management................................................................................................................................................... 19
Virtual disk features..........................................................................................................................................................19
Virtual disk write cache policies............................................................................................................................... 20
Virtual disk read cache policies.................................................................................................................................20
Virtual disk migration.................................................................................................................................................. 21
Virtual disk initialization.............................................................................................................................................. 21
Reconguration of virtual disks................................................................................................................................22
Background operations..............................................................................................................................................24
Hard drive features.......................................................................................................................................................... 24
Self-Encrypting Disks................................................................................................................................................ 24
Instant Secure Erase..................................................................................................................................................25
4 KB sector disk drives..............................................................................................................................................25
Fault tolerance..................................................................................................................................................................25
The SMART feature...................................................................................................................................................25
Patrol Read................................................................................................................................................................. 26
Physical disk failure detection...................................................................................................................................26
Using persistent hot spare slots...............................................................................................................................26
Physical disk hot swapping....................................................................................................................................... 27
Using replace member and revertible hot spares...................................................................................................27
Controller cache preservation...................................................................................................................................27
Contents 3

Battery Transparent Learn Cycle..............................................................................................................................28
4 Deploying the PERC card............................................................................................................................ 29
Removing the PERC H740P adapter............................................................................................................................ 29
Installing the PERC H740P adapter...............................................................................................................................30
Removing the PERC H740P mini monolithic.................................................................................................................31
Installing the PERC H740P mini monolithic.................................................................................................................. 32
Removing the PERC H745P MX adapter card............................................................................................................ 33
Installing the PERC H745P MX adapter card...............................................................................................................34
Removing the PERC H840 card.................................................................................................................................... 35
Installing the PERC H840 card.......................................................................................................................................36
Part replacement of a PERC card in eHBA mode........................................................................................................36
5 Driver installation......................................................................................................................................... 37
Creating the device driver media................................................................................................................................... 37
Downloading drivers from the Dell support website.............................................................................................. 37
Downloading drivers from the Dell systems service and diagnostic tools media ..............................................38
Windows driver installation............................................................................................................................................. 38
Installing the driver during a Windows Server 2012 R2 and newer installation........................................................ 38
Installing the driver after Windows Server 2012 R2 and newer installation ............................................................ 38
Updating PERC 10 driver for existing Windows Server 2012 R2 and newer............................................................39
Linux driver installation.................................................................................................................................................... 39
Installing or updating the RPM driver package with KMOD support..................................................................40
Installing or updating the RPM driver package with KMP support..................................................................... 40
Loading the driver during operating system installation........................................................................................40
6 Firmware......................................................................................................................................................42
Installing the rmware using DUP..................................................................................................................................42
7 HII conguration utility.................................................................................................................................43
Entering the HII conguration utility.............................................................................................................................. 43
Exiting the HII conguration utility.................................................................................................................................43
Navigating to Dell PERC 10 conguration utility.......................................................................................................... 43
HII Conguration utility Dashboard View options.........................................................................................................44
Conguration management............................................................................................................................................ 45
Auto Congure RAID 0..............................................................................................................................................45
Creating virtual disks................................................................................................................................................. 45
Conguring virtual disk parameters.........................................................................................................................45
Creating prole based virtual disk............................................................................................................................ 46
Viewing Disk Group Properties.................................................................................................................................47
Deleting Congurations............................................................................................................................................. 47
Controller management...................................................................................................................................................47
Clearing controller events......................................................................................................................................... 47
Saving controller events............................................................................................................................................48
Saving debug log........................................................................................................................................................48
Managing link speed.................................................................................................................................................. 48
4Contents

Restoring factory default settings........................................................................................................................... 48
Manage controller mode........................................................................................................................................... 49
Changing prole using HII Conguration Utility......................................................................................................49
Advanced controller properties................................................................................................................................50
Virtual disk management.................................................................................................................................................52
Virtual disk numbering...............................................................................................................................................52
Viewing virtual disk properties..................................................................................................................................52
Viewing physical disks associated with a virtual disk.............................................................................................53
Conguring virtual disk policies................................................................................................................................54
Conguring Virtual Disks...........................................................................................................................................54
Performing break mirror operation.......................................................................................................................... 55
Performing expand virtual disk operation............................................................................................................... 55
Performing consistency check.................................................................................................................................55
Physical disk management..............................................................................................................................................56
Viewing physical disk properties.............................................................................................................................. 56
Cryptographic erase.................................................................................................................................................. 58
Physical disk erase..................................................................................................................................................... 58
Assigning global hot spare........................................................................................................................................ 58
Assigning dedicated hot spare................................................................................................................................. 59
Convert to RAID capable.......................................................................................................................................... 59
Convert to Non-RAID disk........................................................................................................................................59
Hardware components....................................................................................................................................................60
Viewing battery properties....................................................................................................................................... 60
Viewing physical disks associated with an enclosure............................................................................................ 60
8 Security key and RAID management............................................................................................................ 61
Security key implementation........................................................................................................................................... 61
Security key management in the HII conguration utility............................................................................................ 61
Local Key Management....................................................................................................................................................61
Creating security key.......................................................................................................................................................62
Changing Security Settings............................................................................................................................................62
Disabling security key...................................................................................................................................................... 62
Creating secured virtual disk.......................................................................................................................................... 63
Securing pre-existing virtual disk................................................................................................................................... 63
Importing secure virtual disk...........................................................................................................................................63
9 Troubleshooting........................................................................................................................................... 64
Adapter at baseport not responding error message....................................................................................................64
BIOS disabled error message..........................................................................................................................................64
Congured disks removed or not accessible error message...................................................................................... 65
Dirty cache data error message.....................................................................................................................................65
Discovery error message................................................................................................................................................ 65
Drive Conguration Changes Error Message...............................................................................................................65
Windows operating system installation errors .............................................................................................................66
Firmware fault state error message...............................................................................................................................66
Extra enclosure error message.......................................................................................................................................66
Contents 5

Foreign conguration found error message..................................................................................................................66
Foreign conguration not found in HII error message.................................................................................................66
Degraded state of virtual disks.......................................................................................................................................67
Memory errors..................................................................................................................................................................67
Preserved Cache State................................................................................................................................................... 67
Security key errors........................................................................................................................................................... 67
Secured foreign import errors...................................................................................................................................67
Failure to select or congure non Self-Encrypting Disks non-SED..................................................................... 68
Failure to delete security key....................................................................................................................................68
Failure of Cryptographic Erase task on secured physical disks............................................................................ 68
General issues...................................................................................................................................................................68
PERC card has yellow bang in device manager..................................................................................................... 68
PERC card not seen in device manager..................................................................................................................68
Physical disk issues..........................................................................................................................................................69
Physical disk in failed state....................................................................................................................................... 69
Unable to rebuild a fault tolerant virtual disk.......................................................................................................... 69
Fatal error or data corruption reported................................................................................................................... 69
Physical disk displayed as blocked........................................................................................................................... 69
Multiple disks become inaccessible......................................................................................................................... 69
Rebuilding a failed physical disk................................................................................................................................70
Virtual disk fails during rebuild using a global hot spare.........................................................................................70
Virtual disk fails during rebuild using a dedicated hot spare..................................................................................70
Physical disk fails during reconstruction on redundant virtual disk......................................................................70
Virtual disk fails rebuild using a dedicated hot spare..............................................................................................70
Physical disk takes a long time to rebuild.................................................................................................................71
SMART errors................................................................................................................................................................... 71
Smart error detected on a physical disk in a redundant virtual disk..................................................................... 71
Smart error detected on a physical disk in a non-redundant virtual disk.............................................................71
Replace member errors................................................................................................................................................... 72
Source disk fails during replace member operation............................................................................................... 72
Target disk fails........................................................................................................................................................... 72
General disk fails.........................................................................................................................................................72
Linux operating system errors........................................................................................................................................ 72
Virtual disk policy is assumed as write-through error message............................................................................72
Unable to register SCSI device error message.......................................................................................................73
Disk carrier LED indicators.............................................................................................................................................. 73
HII error messages........................................................................................................................................................... 74
Unhealthy Status of the Drivers...............................................................................................................................74
10 Appendix RAID description......................................................................................................................... 75
Summary of RAID levels..................................................................................................................................................75
RAID terminology............................................................................................................................................................. 76
Disk striping.................................................................................................................................................................76
Disk mirroring..............................................................................................................................................................76
Spanned RAID levels..................................................................................................................................................77
Parity data................................................................................................................................................................... 77
6Contents

11 Getting help................................................................................................................................................ 78
Contacting Dell EMC....................................................................................................................................................... 78
Documentation feedback................................................................................................................................................ 78
Contents 7

Overview
The PowerEdge RAID Controller (PERC) 10 Series of cards consist of the H740P, H745P MX, and H840 cards. The PERC 10 family of
storage controller cards has the following characteristics:
• Complies with serial-attached SCSI (SAS) 3.0 providing up to 12 Gb/sec throughput.
• Supports Dell-qualied serial-attached SCSI (SAS) hard drives, SATA hard drives, and solid-state drives (SSDs).
NOTE: Mixing SAS and SATA drives within a virtual disk is not supported. Also, mixing hard drives and SSDs within a virtual
disk is not supported.
NOTE: Mixing disks of dierent speed (7,200 rpm, 10,000 rpm, or 15,000 rpm) and bandwidth (3 Gbps, 6 Gbps or 12 Gbps)
while maintaining the same drive type (SAS or SATA) and technology (HDD or SSD) is supported.
•Oers RAID control capabilities which include support for RAID levels 0, 1, 5, 6, 10, 50, and 60.
• Provides reliability, high performance, and fault-tolerant disk subsystem management.
Topics:
• Supported operating systems
• PERC card specications
• Management applications for PERC cards
• Related documentation
Supported operating systems
The PERC 10 series cards support the following operating systems:
NOTE: For more information on the supported operating systems supported by a specic server, see www.dell.com/support
• Microsoft
– Windows Server 2012 R2
– Windows Server 2016
– Windows Server 2019
• VMware
– ESXi 6.5 Update 2
– ESXi 6.7 Update 1
NOTE: The PERC 10 driver for VMware ESXi is bundled with the VMware ISO image available from Dell. For more information,
see Dell.com/virtualizationsolutions.
• Linux
– Red Hat Enterprise Linux version 6.10
– Red Hat Enterprise Linux version 7.5
– SUSE Linux Enterprise Server version 15
– XenServer 7.1.1
– Ubuntu 18.04.1
1
8 Overview

PERC card specications
The table below lists and describes the dierent PERC cards that comprise the PERC 10 series and their specications:
Table 1. PERC cards
Feature PERC H740P PERC H745P MX PERC H840
RAID Levels 0, 1, 5, 6, 10, 50, 60 0, 1, 5, 6, 10, 50, 60 0, 1, 5, 6, 10, 50, 60
Enclosures per port Not applicable Not applicable 4
Processor Dell Adapter SAS RAID-on-Chip,
8-port with LSI 3508 chipset
Dell Adapter SAS RAID-on-Chip,
16-port with LSI 3516 chipset
Dell Adapter SAS RAID-on-
Chip, 8-port with LSI 3508
chipset
Battery Backup Unit Yes Yes Yes
Non-Volatile cache Yes Yes Yes
Cache memory 8 GB DDR4 2133 Mhz cache 8 GB DDR4 2133 Mhz cache 8 GB DDR4 2133 Mhz cache
Cache function Write Back, Write Through, No
Read Ahead, and Read Ahead
Write Back, Write Through, No
Read Ahead, and Read Ahead
Write Back, Write Through, No
Read Ahead, and Read Ahead
Maximum number of virtual
disks, RAID mode
64 240 240
Maximum number of disks,
Enhanced HBA mode
240 - combination of virtual disks
and Non-Raid disks.
240 - combination of virtual
disks and Non-Raid disks.
N/A
Maximum number of virtual disks
per disk group
16 16 16
Hot swap devices supported Yes Yes Yes
Hardware XOR Engine Yes Yes Yes
Online capacity expansion Yes Yes Yes
Dedicated and global hot spare Yes Yes Yes
Drives Types 3 Gbps SATA, 6 Gbps SATA/
SAS, and 12 Gbps SAS
3 Gbps SATA, 6 Gbps SATA/
SAS, and 12 Gbps SAS
6 Gbps SAS, and 12 Gbps SAS
PCIe Support Gen 3 Gen 3 Gen 3
NOTE: Enhanced HBA mode is supported from rmware version 50.5.0-1750 (or later).
NOTE: 240 virtual disks can be created only in PD240 prole, for more information see Prole Management.
Management applications for PERC cards
Dell OpenManage Storage Management applications enable you to manage and congure the RAID system, create and manage multiple
disk groups, control and monitor multiple RAID systems, and provide online maintenance. The management applications for all PERC cards
include:
• Comprehensive Embedded Management
• Dell OpenManage Storage Management
Overview 9

• Human Interface Infrastructure (HII) Conguration Utility
• PERC CLI
NOTE: The BIOS conguration utility <Ctrl> <R> is not supported on the PERC 10 cards.
Comprehensive embedded management
Comprehensive Embedded Management (CEM) is a storage management solution for Dell systems that enables you to eectively monitor
the RAID and network controllers installed on the system using iDRAC without an OS installed on the system.
Using CEM enables you to perform the following:
• Monitor devices without an OS installed on the system.
• Provide a specic location to access monitored data of the storage devices and network cards.
• Allows controller conguration for all the PERC 10 cards (H740P and H840).
NOTE: If you boot the system to HII (F2) or Lifecycle Controller (F10), then you cannot view the PERC cards on the CEM GUI.
The PERC cards are displayed on the CEM GUI only after the system boot is complete.
Dell OpenManage Storage Management
The Dell OpenManage Storage Management is a storage management application for Dell systems that provides enhanced features for
conguring a system's locally-attached RAID disk storage. The Dell OpenManage storage management application enables you to perform
controller and enclosure functions for all supported RAID controllers and enclosures from a single graphical or command-line interface. The
graphical user interface (GUI) is wizard-driven with features for novice and advanced users, and detailed online help. Using the Dell
OpenManage storage management application, you can protect your data by conguring data-redundancy, assigning hot spares, or
rebuilding failed physical disks. The command line interface available on selected operating systems to perform RAID management tasks is
fully featured and scriptable.
NOTE: For more information, see the
Dell OpenManage Storage Management User's Guide at Dell.com/openmanagemanuals.
Related documentation
NOTE:
• For all storage controllers and PCIe SSD documents, go to Dell.com/storagecontrollermanuals.
• For all Dell OpenManage documents, go to Dell.com/openmanagemanuals.
• For all operating system documents, go to Dell.com/operatingsystemmanuals.
• For all PowerEdge documentation, go to Dell.com/poweredgemanuals.
10 Overview

Getting Started
The Dell PowerEdge RAID Controller (PERC) 10 Series of cards consist of the H740P, H745P MX, and H840 cards.
•PERC H740P: The PERC H740P is the performance RAID solution card consisting of 8 GB Non-Volatile Cache and is available in the
Adapter (low prole and full height) and Mini Monolithic form factors for internal storage.
Figure 1. Features of PERC H740P adapter
1heat sink 2 battery
3 battery cable 4 battery-cable connector
5 port B 6 port A
Figure 2. Features of PERC H740P mini monolithic card
1heat sink 2 battery
2
Getting Started 11

3 battery cable
•PERC H745P MX: The PERC H745P MX is the MX7000 RAID solution card consisting of 8 GB Non-Volatile Cache that manages
drives internally and in the MX5017 storage enclosure.
Figure 3. Features of PERC H745P MX adapter
1 Mezzanine connector 2 release lever
3 heat sink 4 SAS-cable connector
5 battery-cable connector 6 battery
•PERC H840: The PERC H840 is similar to the H740P solution, except that it supports external storage. The PERC H840 is only
available in the Adapter (low prole and full height) form factor.
Figure 4. Features of PERC H840 adapter card
1heat sink 2 battery
3 battery cable 4 battery-cable connector
5 port B/1 6 port A/0
12 Getting Started

Features
Controller features
This section lists the following controller features supported on PowerEdge RAID Controller (PERC) 10 cards in detail:
• FastPath
• Disk roaming
• 1 MB IO
• Physical disk power management
• Auto Congure RAID0
• Secure rmware update
• PERC H840 enclosure support
• Redundant path support for PERC H840
•Prole Management
FastPath
FastPath is a feature that improves application performance by delivering high I/O per second (IOPs) for Solid State Drives (SSD). The Dell
PowerEdge RAID Controller (PERC) 10 series supports FastPath.
To enable FastPath on a virtual disk the Dell PowerEdge RAID Controller (PERC) 10 series cache policies need to be set to Write-Through
and No Read Ahead. This enables FastPath to use the proper data path through the controller based on command (read/write), IO size,
and RAID type.
Disk roaming
Disk roaming is moving the physical disks from one cable connection or backplane slot to another on the same controller. The controller
automatically recognizes the relocated physical disks and logically places them in the virtual disks that are part of the disk group. You can
perform disk roaming only when the system is turned o.
CAUTION: Do not attempt disk roaming during RAID level migration (RLM) or online capacity expansion (OCE). This causes loss
of the virtual disk.
Using disk roaming
Perform the following steps to use disk roaming:
1 Turn o the power to the system, physical disks, enclosures, and system components.
2 Disconnect power cables from the system.
3 Move the physical disks to desired positions on the backplane or the enclosure.
4 Perform a safety check. Make sure the physical disks are inserted properly.
5 Turn on the system.
The controller detects the RAID conguration from the conguration data on the physical disks.
3
Features 13

1 MB IO
The H740P and H840 controllers support 1 MB IO feature. If the capacity of IO frame is greater than 1 MB, the IO frame is broken into
smaller chunks.
Physical disk power management
Physical disk power management is a power-saving feature of the PERC 10 series cards. The feature allows disks to be spun down based
on disk conguration and I/O activity. The feature is supported on all rotating SAS and SATA disks and includes uncongured and hot-spare
disks. The physical disk power management feature is disabled by default. You can enable the feature in the Dell Open Manage Storage
Management application or in the Human Interface Infrastructure (HII) Conguration utility. For more information on HII conguration
and physical disk power management, see Enabling Physical Disk Power Management. For more information on using the Dell Open
Manage Storage Management application, see the Dell OpenManage documentation at Dell.com/openmanagemanuals.
Secure rmware update
This feature provides a cryptographic method of updating the rmware using RSA encryption-decryption algorithm.
Only Dell certied rmware is supported on your PERC controller.
Enhanced HBA mode
Enhanced HBA mode (eHBA mode) is a new operating mode available with H740P and H745P MX cards. eHBA provides the following
features:
• Create virtual disks with RAID level 0, 1, or 10.
• Present Non-RAID disks to the host.
•Congure a default cache policy for virtual disks is write-back with read ahead.
•Congure virtual disks and Non-RAID disks as valid boot devices
• Automatically convert all uncongured disks to Non-RAID:
– On system boot
– On controller reset
– When uncongured disks are hot-inserted
NOTE: Creating or Importing RAID 5, 6, 50, or 60 virtual disks are not supported.
NOTE: Older versions of OpenManage Storage Management and Comprehensive Embedded Management do not support
management of the controller in Enhanced HBA mode.
NOTE: In enhanced HBA mode, non-RAID disks are enumerated rst in ascending order, while RAID volumes are enumerated in
descending order.
NOTE: For more information, see the applicable systems management documentation.
14 Features

Table 2. PERC cards with eHBA mode enabled
Feature eHBA mode (H740P and H745P MX only)
RAID levels 0, 1, and 10
Host I/O command queue depth 5120 (H740P)
Maximum supported PDs Max (240)
4KB drives Yes
Write Back caching Yes (VDs only)
SED support Yes, local key management
Battery maintenance Yes
Patrol Read Yes (VDs only)
Controller and battery Diagnostics Yes
Non-RAID disks
A Non-RAID disk is a single disk to the host, and not a RAID volume. The only supported cache policy for Non-RAID disks is write-through.
Auto Congure RAID 0
Auto Congure RAID 0 feature creates a single drive RAID 0 on each physical disk that is in the ready state. For more information, see Auto
Congure RAID 0.
PERC H745P MX enclosure support
The H745P MX is a RAID controller for the PowerEdge MX740c and MX840c compute sleds. It is used as an interface in a multipath
topology with the MX5016s storage sled for the MX7000 modular system. The following illustration describes the multipath topology for
the MX7000 modular system:
Features 15

Figure 5. Multipath topology for the MX7000 modular system
In this illustration, the H745P MX resides in the compute sled and functions as an interface to the SAS topology of the MX7000. The
H745P MX is used to congure drives that are located in the MX5016s storage sled into RAID volumes. The H745P MX connects to a pair
of MX5000s SAS I/O modules (IOMs) that manage connections between the compute and storage sleds in the MX7000. For more
information about conguring drive assignments, see the Dell.com/openmanagemanuals > OpenManage Enterprise Modular.
NOTE: The I/O modules cannot be congured independently.
The H745P MX is connected to the SAS IOM, which in turn connects to one of the SAS expanders in the storage sled. The expander in the
storage sled is then connected to all the physical drives in the storage sled, providing one path between the H745P MX and a physical drive
in the storage sled. With connections to both SAS IOMs, the H745P MX has two paths to each drive in a storage sled allowing for a multi-
path conguration. If either a SAS IOM or a SAS expander in the storage sled is removed, then a path to the physical drive is removed from
the SAS topology.
16 Features

PERC H840 enclosure support
The H840 card is an external card. The H840 card supports:
• up to eight enclosures using single path conguration.
• up to four enclosure using multipath conguration.
To set up a conguration with redundant paths, both ports on a controller must be cabled to the ports of a single enclosure.
NOTE: The PERC H840 card supports redundant paths when used with Dell PowerVault MD14XX series disk storage
enclosures.
NOTE: The Enhanced HBA mode is not supported on PERC H840.
Figure 6. PERC H840 card ports — Four enclosures with multipath conguration
To set up an enclosure on the PERC H840 card:
a To connect multiple enclosures, two cables connect the rst enclosure to the second enclosure, then two more cables connect
the second enclosure to the third enclosure.
b To connect a single enclosure, cable the ports so that the enclosure is connected to both the ports on the controller card.
Features 17

Figure 7. PERC H840 card ports — Eight enclosures with single path conguration
Redundant path support for PERC H840
The PERC H840 adapter can detect and use redundant paths to disks contained in enclosures. This provides the ability to connect two
SAS cables between a controller and an enclosure for path redundancy. The controller can tolerate the failure of a cable or Enclosure
Management Module (EMM) by utilizing the remaining path. When redundant paths exist, the controller automatically balances I/O load
through both paths to each disk. Load balancing increases throughput to virtual disks in storage enclosures and is automatically turned on
when redundant paths are detected. To set up your hardware to support redundant paths, see Setting up redundant path support on the
PERC H840 adapter.
NOTE: This is applicable for PERC H840 only.
NOTE: This support for redundant paths refers to path redundancy only and not to controller redundancy.
18 Features

Setting up redundant path support on the PERC H840 adapter
The PERC H840 card can detect and use redundant paths to disks contained in enclosures. With redundant paths to the same device, if
one path fails, another path can be used to communicate between the controller and the device.
To connect single enclosure, cable the ports so that the enclosure is connected to both the ports on the controller card. See Figure 6.
PERC H840 Card ports - Four enclosures with multipath conguration in PERC H840 enclosure support.
Prole Management
PERC 10 introduces the concept of proles. A prole is user selectable. It denes controller queue depth and the maximum number of
physical and virtual disks. There are two proles: PD64 and PD240. The H740 supports only the PD64 prole. The H745P MX supports only
the PD240 prole. The H840 supports both PD64 and PD240. PD240 is the default prole on H840. For more information see Changing
prole using HII Conguration Utility.
NOTE: When H740 or H840 controller is upgraded to 50.3.0-1022 from an older rmware, prole on the controller is set to PD64.
Table 3. Supported Proles on PERC 10
Feature PD64 PD240
Prole ID 10 12
Maximum physical disk supported 64 240
Maximum virtual disk supported 64 240
Controller queue depth 4096 3072
Maximum enclosure supported • One enclosure using multipath
conguration
• Two enclosure using single path
conguration
• Four enclosure using multipath conguration
• Eight enclosure using single path
conguration
NOTE: In the MX chassis, H745P MX supports seven enclosures using a multipath
conguration.
NOTE: PD64 is supported on internal and external controllers, whereas PD240 is supported on the H840 and H745P MX.
Virtual disk features
This section lists the following virtual disk features supported on PowerEdge RAID Controller (PERC) 10 cards in detail:
• Virtual disk write cache policy
• Virtual disk read cache policy
• Virtual disk migration
• Virtual disk Initialization
•Reconguration of virtual disk
• Background operations
Features 19

Virtual disk write cache policies
The write cache policy of a virtual disk determines how the controller handles writes to the virtual disk.
Table 4. Write cache policies
Feature Description
Write-Back The controller sends a data transfer completion signal to the host
when the controller cache has received all the data in a transaction.
The controller then writes the cached data to the storage device in
the background.
NOTE: The default cache setting for virtual disks is Write-
Back caching. Write-back caching is also supported for
single drive RAID 0 virtual disks.
Write-Through The controller sends a data transfer completion signal to the host
system when the disk subsystem has received all the data in a
transaction.
All RAID volumes are presented as Write-Through to the operating
system (Windows and Linux) independent of the actual write cache
policy of the virtual disk. The PERC cards manage the data in cache
independently of the operating system or any applications.
NOTE: Certain data patterns and congurations perform
better with a Write-Through cache policy.
NOTE: Use the Dell OpenManage storage management application or the HII Conguration Utility to view and manage virtual
disk cache settings.
Conditions under which write-back is employed
Write-Back caching is used under all conditions in which the battery is present and in good condition.
Conditions under which forced write-back with no battery is employed
CAUTION: It is recommended that you use a power backup system when forcing Write-Back to ensure there is no loss of data if
the system suddenly loses power.
Write-Back mode is available when you select Force WB with no battery. When Forced Write-Back mode is selected, the virtual disk is in
Write-Back mode even if the battery is not present.
Virtual disk read cache policies
The read policy of a virtual disk determines how the controller handles reads to that virtual disk.
20 Features