Sonnet Fusion RAID Storage Systems User manual

Configuration Tool and Utilities v3.25
Operation Manual
for Fusion RAID Storage Systems

1.0 ATTO Configuration Tool Overview............................................................................................. 1
About the Configuration Tool
Configuration Tool Launch
Configuration Tool Navigation
Select the Local Host
Select a Controller
Select a Channel
Select a Device
1.1 NVRAM Settings........................................................................................................................7
SAS Address
Boot Driver
NCQ
Heartbeat
Device Wait Time
Device Wait Count
Spinup Delay
1.2 RAID Group Setup and Management...........................................................................................9
Preliminary Configuration Steps
Custom RAID Group Setup
Hot Spares Setup and Usage
Mac OS Drive Formatting
Windows Drive Formatting
RAID Group Management Overview
RAID Group Capacity Expansion
RAID Level Migration
RAID Group Deletion
RAID Group Rebuilding
RAID Group Properties Modification
1.3 Drive and RAID Group Monitoring............................................................................................17
Basic Drive Information
Detailed Drive Information
RAID Group Information
Drive Identification
S.M.A.R.T. Data
S.M.A.R.T. Monitoring Enabling and Disabling
S.M.A.R.T. Status Checking
S.M.A.R.T. Attribute Filtering
S.M.A.R.T. Notifications
1.4 Enclosure (SES) Health Monitoring...........................................................................................21
SES Status Checking
Contents

Contents
1.5 Notifications.......................................................................................................................... 23
Basic Alerts
Logging
Email Alert
1.6 Diagnose and Replace a Faulted Drive......................................................................................25
Automatic Faulted Drive Identification
Manual Faulted Drive Identification
Faulted Drive Replacement with Auto Rebuild
Manual Faulted Drive Replacement
1.7 RAID Group Media Maintenance............................................................................................... 27
Media Scan Options
Start a Manual Media Scan
Schedule a Media Scan
Cancel, Pause, or Resume a Media Scan
Manage Scheduled Media Scans
Automatic Media Scan Cancellation
View a Scan Report
1.8 SNMP Configuration................................................................................................................ 33
Definitions
Details
Enabled Mode
SubAgent Mode
Disabled Mode
Basic Setup
Configuration Options
Agent Port
Communities
Send Authentication Trap.
Enable Traps
Trap Destination Table
Control Buttons
Commit
Restore
Default
Test
Save MIBs
Troubleshooting
Requests from an MIB browser time out:
Traps are not received when testing
The RAID OIDs are skipped when walking or the tables are empty

Contents
1.9 Configuration Tool Troubleshooting..........................................................................................39
Messages from NVRAM Tab Actions
An error occurred loading NVRAM data.
Warning: NVRAM could not be read, defaults returned.
An error occurred updating the NVRAM.
Feature bounds checking.
Execution Throttle is greater than the maximum allowable value of 255.
Messages from Flash Tab Actions
This is not a flash file, or it is corrupt.
This HBA is not compatible with the selected flash file.
A valid file was not selected.
An error occurred reading from the flash file, the file may be corrupt.
An error occurred updating the flash.
The card has been prepared for firmware updating…
2.0 Drive Performance Testing.......................................................................................................41
2.1 Windows Only - ATTO Disk Benchmark..................................................................................... 43
Benchmark Fields
Radio Button Group
Multiple Benchmark Testing
2.2 ATTO Disk Benchmark Troubleshooting.....................................................................................45
Appendix A - CLI ASCII-Based Interface........................................................................................... i
CLI Error Messages
CLI Summary
CLI Command Explanations
Appendix B - Quick Drive Reformat Instructions............................................................................xiv
Mac OS Users’ Instructions
Windows Vista Users’ Instructions
Windows XP/Server 2003 Users’ Instructions

1
About the Configuration Tool
The ATTO Configuration Tool is the utility program that displays
information about installed controllers, drivers and drives in your
Fusion storage system, and provides the means to configure and
manage them.
This program executes under:
• Mac OS®X 10.4 or later
• Windows®Vista/XP/Server 2008/2003/2000
• Linux®2.4 and 2.6 kernels, x86 and x64
Note: Java version 1.5 or later must be installed.
The ATTO Configuration Tool displays:
• The name of the Sonnet RAID controller (listed as an ExpressSAS
Rxxx adapter)
• Information about the drivers controlling the Sonnet RAID
controller, including version information for both the currently
executing driver and the flash image
• Information about drives attached to the Sonnet RAID controller
• Information about the connected Fusion drive enclosure (except
D400RAID, D800RAID, and R800RAID) such as fan and power
supply status
You may use the Configuration Tool to:
• Manage RAID groups
• Congure RAID Event notications
• Modify the RAID controller’s NVRAM settings
• Revert to default factory settings
• Update the RAID controller’s ash image
• Obtain drive health information
• Obtain drive enclosure health information
The factory settings on your Sonnet RAID controller provide
excellent performance for a wide range of applications. However,
some applications may benet from modication of the
controller’s NVRAM settings that tune the controller for a specic
performance range.
Configuration Tool Launch
1. Locate the application icon in the folder created during
installation.
2. Double-click the ATTO Conguration icon to start the
application.
Note: The Sonnet RAID controller is designed to operate properly using
factory settings. Entering invalid or incorrect NVRAM settings
may cause your Sonnet RAID controller to function incorrectly.
The main screen has three panes: Device Listing, Conguration
Options and Status.
Configuration Tool Navigation
The Device Listing pane at the left of the window lists all
compatible devices (controllers and enclosures) currently
connected to the system.
Expand the device tree to reveal additional detail on connected
devices.
The Conguration Options pane provides information and
options for a device highlighted in the device listing.
If you highlight a device in the Device Listing pane, tabs and
panes are displayed for that device.
The following chart species the tabs that are displayed for the
indicated device type.
Tree Node Tab(s) Displayed
Local Host Basic Info, Notications, SNMP
Controller Basic Info, Flash, RAID, RAID CLI, Tasks,
Advanced
Channel NVRAM, PCI Info
Device Basic Info, Flash, SES
1.0 ATTO Configuration Tool Overview
Support Note: In the Device Listing pane of the ATTO
Configuration Tool window, the Sonnet RAID controller is
identified as an ExpressSAS Rxxx.
WARNING: Back up system data when installing or
changing hardware configurations.

2
Select a Channel
The following tabs display in the Conguration Options pane
when you select a specic channel in the Device Listing pane:
• When you select a specic channel under the Sonnet RAID
controller in the Device Listing pane, the NVRAM tab displays
the NVRAM parameters applicable to the Sonnet RAID
controller and channel selected. Refer to NVRAM Settings on
page 7, and Conguration Tool Troubleshooting on page 27
for information about NVRAM settings.
• The Sonnet RAID controller’s information is displayed in the
PCI Info tab. See Figure 7 on page 6.
• The current status of the Configuration Tool is represented in
the Status pane at the bottom of the window.
About window
The About window, displayed when About is selected from the
Help menu, lists the ATTO Conguration Tool’s version number.
Select a Device
The following tabs display in the Configuration Options pane
when you select a specic device in the Device Listing pane:
• The Basic Info tab displays information about the selected
enclosure or SAS expander.
• The Flash tab does not function with the Fusion storage
systems; clicking this tab merely displays a message.
• The SES tab displays SES (SCSI Enclosure Services) status
information for SES devices such as power supplies and fans.
See Figure 8 on page 6.
1.0 ATTO Configuration Tool Overview
Select the Local Host
The following tabs display in the Conguration Options window
when you select the local host in the Device Listing window:
• The Basic Info tab displays information about the booted
operating system. See Figure 1 on page 3.
• The Notifications tab allows you to set up notication
of certain events in the Sonnet RAID controller. Refer to
Notications on page 23.
• The SNMP tab allows you to congure SNMP monitoring and
trap generation for the Sonnet RAID controller. Refer to SNMP
Conguration on page 33.
About window
The About window, displayed when About is selected from the
Help menu, lists the ATTO Conguration Tool’s version number.
Select a Controller
The following tabs are displayed in the Conguration Options
pane when you select the Sonnet RAID controller in the Device
Listing pane:
• The Basic Info tab provides information about the Sonnet
RAID controller when it is highlighted in the Device Listing
pane. You cannot make changes from this screen. See Figure
2on page 3.
• The Flash tab provides information about the current flash
version programmed on the highlighted controller. See Figure
3on page 4.
Click the Browse button at the bottom of the tab to search for
new ash les on your system such as FlashBundle_2007_02_
27.R380. Once you’ve selected the ash le, click the Update
button to automatically update your Sonnet RAID controller.
• The RAID tab provides information about attached drives,
their RAID group and hot spare associations, and their
operating status. From the RAID tab, you can create, modify,
and delete RAID groups. See Figure 4 on page 4.
• The RAID CLI tab provides access to the command line
interface, which, as an alternative to application menu-based
commands, enables the use of ASCII-based commands to
control conguration and diagnostic tasks. See Figure 5 on
page 5.
• The Tasks tab provides information about user-scheduled hard
drive health maintenance. In this tab, you can reschedule or
delete tasks. See Figure 6 on page 5.
• The Advanced tab does not function with the Sonnet RAID
controller; clicking this tab merely displays a message.
Support Note: This feature does not work with Fusion
D400RAID, Fusion D800RAID, nor Fusion R800RAID
storage systems.
Support Note: The SES tab appears only when an
enclosure with one or two SAS expanders, such as Fusion
DX800RAID, or Fusion RX1600RAID, is used.

3
Figure 1
Figure 2
1.0 ATTO Configuration Tool Overview
Basic Info displayed when Local Host chosen in the Device Listing pane
Basic Info displayed when the Sonnet RAID controller is chosen in the Device Listing pane

4
Figure 3
Figure 4
1.0 ATTO Configuration Tool Overview
Flash information displayed when the Sonnet RAID controller is chosen in the Device Listing pane
RAID group and associated drive information displayed when the Sonnet RAID controller is chosen in the Device Listing pane

5
Figure 6
1.0 ATTO Configuration Tool Overview
Tasks information displayed when the Sonnet RAID controller is chosen in the Device Listing pane
Figure 5
RAID CLI displayed when the Sonnet RAID controller is chosen in the Device Listing pane

6
Figure 7
PCI Info tab
1.0 ATTO Configuration Tool Overview
Figure 8
SES information displayed when a SAS expander is selected in the Device Listing pane

7
1.1 NVRAM Settings
The settings in the NVRAM tab vary depending upon the operating
system.
The Sonnet RAID controller is designed to operate properly using
factory settings. Entering invalid or incorrect settings when using
an NVRAM conguration utility such as the ATTO Conguration
Tool may cause your controller to function incorrectly. See
Figure 9 on page 8.
Use caution when making changes to NVRAM settings and only
make changes to those with which you are familiar. Once you
have made the desired changes, click Commit to save the changes.
Click Save to name and save an NVRAM conguration. Click Load
to load a saved NVRAM conguration. Changes do not take effect
until you reboot the system.
If you do not want to make any changes, you may choose one of
the following:
• Defaults: restores the controller to factory default settings. The
Commit button must be clicked to save any changes.
• Restore: reverts to the NVRAM settings saved the last time the
Commit button was used. Clicking Commit is not necessary.
SAS Address
Read only
Displays the SAS address assigned to the controller. The value
cannot be modied.
Boot Driver (Windows only)
Choices: enabled, scan only, disabled
Default: disabled
If enabled and disk drives are detected during the bus scan, the
BIOS driver remains resident. If disabled, the BIOS starts, resets
the controller chip and unloads the driver.
If Scan Only is selected, the BIOS driver scans the bus and displays
the devices attached, then unloads itself after a brief delay.
Heartbeat
Choices: enabled, disabled
Default: enabled
When enabled, the Sonnet RAID controller’s rmware is required
to respond to periodic activity. If the rmware does not respond,
the system driver resets the rmware on the controller.
WARNING: Back up system data when installing or
changing hardware configurations.
NCQ
Choices: enabled, scan only, disabled
Default: disabled
When enabled, the Sonnet RAID controller’s driver sends
multiple simultaneous commands to NCQ-capable SATA disk
drives. This may be useful when the Fusion storage system is used
in database applications, but may hinder performance in video
editing and other applications.
Device Wait Time
Choices: 1–255 seconds
Default: 3
Species the number of seconds that the driver waits for devices
to appear.
Device Wait Count
Choices: 1–255 devices
Default: 1
Species the number of devices that must appear in order to cancel
the Device Wait Time period.
Spinup Delay
Choices: 0-20 seconds
Default: 0
Species the number of seconds each SAS port waits for disk drives
to spin up.
Support Note: The SAS address is a globally-unique
identifier assigned to devices such as the Sonnet RAID
controller, and is similar to an Ethernet adapter’s MAC address.

8
Figure 9
1.1 NVRAM Settings
NVRAM settings information shown when a Fusion drive enclosure is selected in the Device Listing pane

9
1.2 RAID Group Setup and Management
The ATTO Configuration Tool enables you to configure disk storage
into RAID groups or Hot Spare drives.
Note: Even an individual JBOD disk is considered to be a RAID group.
Use the ATTO Conguration Tool to set up RAID groups on your
Sonnet RAID controller in one of the following RAID levels:
• JBOD
• RAID Level 0
• RAID Level 1
• RAID Level 4
• RAID Level 5
• RAID Level 6
• RAID Level 10
• DVRAID™
DVRAID RAID groups may be set up automatically by the ATTO
Conguration Tool. All other RAID congurations require
customized input; Sonnet recommends Custom RAID Group
setup.
Each RAID group may be divided into one or more partitions;
each partition appears to the your computer as a virtual disk.
You may use the command line interface pane from the RAID
CLI tab in the ATTO Conguration Tool to set up or modify
various parameters (Refer to Appendix A). However, using the
menu-based procedures listed in this chapter is the preferred
method for setting up RAID configurations for the Fusion
storage system.
Preliminary Configuration Steps
1. Launch the ATTO Conguration Tool application.
2. The Conguration Tool main screen appears. In the Device
Listing pane on the left side of the window, click ExpressSAS
Rxxx under localhost; a new set of tabs appears in the right
pane. See Figure 10 on page 13 for an overview.
3. Click the RAID tab; attached drives are displayed in the top
pane, while RAID groups and Hot Spares are displayed in the
bottom pane.
Custom RAID Group Setup
1. After completing Preliminary Conguration Steps, select
RAID Management > Create Group > Customized from the
application menu.
2. Select the rst set of options to congure the new RAID
group. See Figure 11 on page 13.
• Name: name the RAID group or use the one assigned by
the Conguration Tool. The name must be unique and no
more than 14 characters.
• Level: select a RAID group level from the drop-down box.
  •Interleave: select an interleave value. The default value
is 128KB. Sonnet recommends 1MB interleave size for
maximum video editing performance.
• Mirror Count: select the number of mirror groups when
RAID 1 or RAID 10 RAID groups are created.
Support Note: In the Device Listing pane of the ATTO
Configuration Tool window, the Sonnet RAID controller is
identified as an ExpressSAS Rxxx.
Windows Support Note: In order to create RAID
volumes larger than 2TB under Windows, you must do one
of the following: Select the 4KB sector size when creating a
custom RAID group (not DVRAID) and select Simple Volume
as the formatting option in the Disk Management application.
-OR- Use the software configuration tools included with the
Fusion storage to create volumes up to 2TB, span (link together
in a virtual chain) the volumes, and then format as NTFS.
- OR- Use GPT formatting. Note that drives and volumes with
GPT formatting are not visible to any version of Windows XP
Professional, nor to the 32-bit version of Windows Server 2003 SP1.
Support Note: DVRAID is a customized, protected
RAID 4 configuration. It is optimized for increased digital
video playback performance when compared to that obtained
from a RAID 5 configuration. DVRAID’s write performance is
decreased in order to accomplish this optimization.
Support Note: Descriptions of RAID levels can be found
on the Wikipedia.org Web site at the following addresses:
http://en.wikipedia.org/wiki/Standard_RAID_levels and
http://en.wikipedia.org/wiki/Nested_RAID_levels.
Support Note: Two RAID groups with the same name
may not be recognized. If you add another RAID group to
your setup, you must make sure it does not have the same name
as the existing one, and change it if it does.
Support Note: The interleave value chosen when
creating a RAID group makes a significant impact on
performance. Fusion RAID storage systems shipped from Sonnet
with pre-installed hard disk drives are now optimized for use
with video editing (larger files) applications, typically with an
interleave value of 512KB or 1MB selected. If you intend to
use your storage system primarily for storage of smaller files
(database, office documents, etc.), choose a smaller interleave
value of 64KB or 128KB.
Support Note: In Fusion RAID systems shipped from
Sonnet with hard drives installed, the drives are formatted
Mac OS Extended (Journaled), configured as a single RAID 5 RAID
group, and ready for use with Mac OS X-based systems. If you
need to change the configuration, delete the existing RAID group
(see RAID Group Deletion on page 12), and use the Configuration
Tool and the operating system software tools to reformat and
reconfigure the drives. See page xiv for Quick Format instructions
for Mac OS and Windows users.

10
1.2 RAID Group Setup and Management
Custom RAID Group Setup (continued)
• Initialize: select Advanced or Express; Sonnet recommends
choosing Advanced.
3. Click Next. Select the drives in the top pane and drag them
into the device area in the bottom pane. See Figure 12 on
page 14.
4. Click Next. Select the next set of options to congure the
new RAID group. See Figure 13 on page 14.
• Sector Size: select a sector size from the drop down box.
The default is 512 bytes. Use 512 bytes unless you need to
use the MBR partition scheme under Windows.
• Speed Read: select Always, Adaptive, or Never. The default
is Adaptive, but Sonnet recommends Always.
• Rebuild Priority: select High, Same, or Low. The default is
Same.
• Auto Rebuild: on or off.
5. If you want the RAID group to be presented as one virtual
disk (partition), click Finish. If you want more than one
virtual disk (partition), click Next (see Figure 14 on page 15),
and then select one of the following options:
• leave as one partition
• partition by count
• partition by size
If you choose to split the RAID group by count or capacity,
you must enter additional information.
6. If you have not already done so, click Finish.
7. A conrmation dialog box asks you to approve the settings
you have chosen. Click Yes.
8. Select the RAID group in the Groups pane.
9. Select RAID Management > Properties from the application
menu. In the Properties window, change the Prefetch value
to 6. See Figure 15 on page 15.
10. Click accept.
11. Click the RAID CLI tab, type “get raidcommandtimeout”
and then hit the return key; if the number that appears is
60000, skip to step 13.
12. Type “set raidcommandtimeout 60000” and then hit the
return key.
13. Every RAID group must finish initializing, and be formatted
by your computer’s operating system software before it becomes
available for use; Mac users will use Disk Utility, Windows
users will use Disk Management. For more information on
drive formatting, see Mac OS Drive Formatting or Windows
Drive Formatting on page 11.
Support Note: When the Advanced Initialize option is
selected, parity blocks are calculated and the RAID group
is thoroughly scanned and subjected to a complete Write/Verify
operation to map out any bad blocks on the drives before the
RAID group is made available for use.
When the Express Initialize option is chosen, drives are not
scanned and subjected to the Write/Verify operation, but parity
blocks are calculated and the RAID group may be used during
the initialization.
Windows Support Note: Choosing the 4K sector size
enables the creation and use of RAID volumes up to 16TB
on systems running Windows XP 32-bit. Otherwise the volumes
are limited to 2TB.
Support Note: For the Speed Read option, select Always
if you expect to work with large sequential files (video, for
example), Never if you expect most of the files to be smaller in
size (general storage, database, etc.), or Adaptive if you expect
mixed use or don’t know.
Support Note: Rebuild priority affects the performance
of your Fusion storage system when a drive is replaced and
a degraded RAID group is rebuilt. Selecting Low rebuild priority
enables you to continue working at the best performance level
possible, but the RAID group will take much longer to rebuild.
Support Note: If the Auto Rebuild option is not checked,
you will have to manually start a RAID group rebuild after
replacing a faulted drive.

11
Hot Spares Setup and Usage
If a drive in a parity RAID group becomes degraded or faulted,
the RAID group will lose some redundancy until a new member
(drive) is rebuilt into it. You can automate this procedure by
designating one or more drives as Hot Spares. You may set up a
pool of Hot Spare drives of different sizes appropriate for your
RAID groups.
If the Sonnet RAID controller detects a faulted drive in a RAID
group with a designated Hot Spare:
• The controller searches the Hot Spare pool for the smallest drive
of sufcient capacity to substitute for the faulted drive.
• The faulted drive is replaced with one from the Hot Spare pool.
• The controller begins an automatic rebuild of the RAID group.
Select RAID Management > New Hot Spare (or Delete Hot Spare)
from the application menu, and then follow the instructions on
the screen.
Mac OS Drive Formatting
1. Depending on how you congure your setup, a Disk Insertion
window stating that there is an unreadable volume will
appear at some point during the RAID group creation process;
click Initialize, and then Disk Utility will open.
2. In the Disk Utility window, each RAID group you created
using the ATTO Conguration Tool will appear as a single
volume. Select the volume, and then click the Erase tab at the
top of the window.
3. Click the Erase button; a window will appear asking you to
approve your choice; click Erase.
4. Repeat steps 2 and 3 for each remaining unformatted RAID
group, and then close Disk Utility.
5. Depending on how you congured the RAID groups, the
volumes may already be mounted and present on the desktop.
If you created a DVRAID, RAID 4, RAID 5, or RAID 6 RAID
group, conguration will take much longer. You may check
on the process by double-clicking the volume name in the
lower pane of the ATTO Configuration Tool window.
6. Once all the RAID groups have been formatted and nish
building, they are ready to use.
1.2 RAID Group Setup and Management
Windows Drive Formatting
1. Select Start > Control Panel > Administrative Tools frrom the
Windows Start menu. In the Administrative Tools window,
double-click Computer Management.
2. In the Computer Management window, click Storage on the
left, and then double-click Disk Management.
3. When the Initialize Disk window appears, click OK.
4. In the Disk Management window, each RAID group you
created will appear (listed as “unallocated”) as a single volume.
Right-click where the word “unallocated” appears, and then
select New Simple Volume.
5. When the Welcome to the New Simple Volume Wizard window
appears, click next to start the process.
6. Follow the remaining steps to complete the process.
Note: If you do not select the quick format option, formatting will take
much longer to complete.
7. Repeat steps 4–6 for each remaining “unallocated” disk.
8. Depending on how you congured the RAID groups, the
volumes may already be available to the system. If you
created a DVRAID, RAID 4, RAID 5, or RAID 6 RAID group,
conguration will take much longer. You may check on the
process by double-clicking the volume name in the lower
pane of the ATTO Configuration Tool window.
9. Once all the RAID groups have been formatted and nish
building, they are ready to use.
RAID Group Management Overview
The ATTO Conguration Tool interface may be used to manage
the replacement of a failed drive, add capacity to a RAID group,
change a RAID group’s current RAID level conguration to a new
one, and change a RAID group’s properties.
The ATTO Conguration Tool interface guides you step by step
through many procedures which allow you to modify your
storage and RAID congurations. Read all support notes and
warnings carefully as you go to ensure the best performance and
use of your storage. Many of these procedures are only available
with drives that are not currently part of a RAID group, are not
designated as a Hot Spare, or were offline when you initially set
up RAID congurations.
WARNING: Data can be compromised or lost when
deleting storage or rearranging storage configurations.
Support Note: An unallocated drive or unallocated
storage is storage which is not part of a RAID group, not
designated as a Hot Spare or was offline when you initially set up
a RAID configuration using the ATTO Configuration Tool interface.
Support Note for Power Mac G5 Users: When
creating RAID groups 16TB or larger, uncheck the Install
Mac OS 9 Drivers checkbox; OS 9 drivers do not support volumes
greater than 16TB.
Support Note: Hard drives in the Hot Spare pool should
be of appropriate capacity to the RAID group so that
smaller drives are not replaced by much larger Hot Spare drives.

12
1.2 RAID Group Setup and Management
RAID Group Capacity Expansion
Select RAID Management > Expand Capacity from the
application menu, and then follow the instructions on the screen.
Depending on the RAID conguration, you may need to add more
than one drive at a time.
RAID Level Migration
Changing a RAID group from one RAID level to another is called
migration. The following migration levels are supported:
• JBOD to RAID Level 0
• JBOD to RAID Level 1
• RAID Level 0 to RAID Level 10
• RAID Level 1 to RAID 10
Select RAID Management > Migrate RAID Level from the
application menu, and then follow the instructions on the screen.
RAID Group Deletion
You may delete a group using the ATTO Conguration Tool.
Select RAID Management > Delete Group from the application
menu, and then follow the instructions on the screen.
RAID Group Rebuilding
If a RAID group becomes compromised, you must rebuild it.
Select RAID Management > Rebuild Group from the application
menu, and then follow the instructions on the screen.
You may pause a RAID group rebuild by selecting the RAID
group in the lower pane, and then selecting RAID Management >
Pause Rebuild from the application menu. To resume the rebuild,
select the RAID group in the bottom pane, and then select RAID
Management > Resume Rebuild from the application menu.
RAID Group Properties Modification
Each RAID group has specic properties, and the value of each
property remains with the RAID group when it is moved from
one computer to another. Some of the properties can only be
specied during RAID group creation (RAID level, interleave, and
sector size), whereas others may be changed at any time during
the life of the RAID group. See Figure 15 on page 15.
1. Select a RAID group in the Groups pane.
2. Select RAID Management > Properties from the application
menu, and then view or change the current properties:
• Speed Read species the cache policy to be used during
read operations. Once a read command is given, the
ExpressSAS RAID code retrieves the next set of sequential
data from the RAID group’s drives and caches it in the
Sonnet RAID controller’s internal memory. If you select
Never, read caching is never performed. If you select
Always, read caching is always performed. If you select
Adaptive, Speed Read is enabled or disabled depending on
the sequential patterns detected in I/O requests.
• Auto Rebuild controls the replacement of a faulted
drive with any available unallocated drive. When you
click the Auto Rebuild check box and the Accept button,
Auto Rebuild is enabled. If a drive becomes faulted, the
ExpressSAS RAID adapter replaces the drive with an
unallocated drive.
• Rebuild Priority species the ratio of rebuild I/O activity
to host I/O activity. A rebuild priority of Same (default
value) indicates that rebuild I/O and host I/O are treated
equally. A rebuild priority of Low indicates that host I/O is
given a higher priority than rebuild I/O. A rebuild priority
of High indicates that rebuild I/O is given a higher priority
than host I/O. In practical terms, selecting Low enables
you to continue working with full read performance, but
the rebuild will take much more time to complete.
• Prefetch species the number of stripes that are read
when Speed Read is enabled or adaptive. The valid values
for prefetch are 0, 1, 2, 3, 4, 5 and 6; the default value is 1.
This property can only be changed after the RAID group is
created. To access this property, select the RAID group and
view its properties.
3. Click Accept.
WARNING: Data can be compromised or lost when
deleting storage or rearranging storage configurations.
Support Note: A RAID group rebuild may take several
hours to complete, depending on the operating system,
drive capacities, and RAID configuration.
WARNING: Adding drives to an existing RAID group may
adversely impact performance. You cannot reverse this
operation unless you delete the RAID group.
Mac User’s Support Note: Although this feature is
supported by the ATTO utility, as of this writing, Mac
OS X does not support RAID group capacity expansion.

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Figure 10
Figure 11
1.2 RAID Group Setup and Management
Configuration Tool main screen with the RAID tab selected
Options selection screen displayed when creating new, custom RAID groups

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Figure 12
Figure 13
1.2 RAID Group Setup and Management
RAID group drives selected
Additional options selection screen displayed when creating new, custom RAID groups