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Configuring PERC 2, 2/Si, 3/Si, and 3/Di RAID Controllers

  Description of Controllers

  Array Manager Storage Model

  Virtual Disk Configuration

  Virtual Disk Management

  Array Group Commands

  Array Disk Commands

  PERC Subsystem Commands

  General Controller Commands

  Managing the Controller Battery

  General Channel Commands

  Array Manager and FAST Compatibility Issues

  Array and Volume Migration

  Naming Convention Differences

This chapter describes how to configure and manage arrays with the following controllers:


Description of Controllers

The PERC 2 RAID controller contains four channels. PERC 2/Si and PERC 3/Si are single integrated channel controllers. The PERC 3/Di is a dual integrated channel controller.

Supported RAID Levels

The PERC 2, PERC 2/Si, PERC 3/Si, and PERC 3/Di controllers support the following RAID levels:

Maximum Virtual Disks per Controller

You can create a maximum of 24 virtual disks on a PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller.


Array Manager Storage Model

Working with these controllers requires an understanding of the Array Manager storage model, which represents the Array Manager storage objects in an object hierarchy. Each object has a set of attributes and operations associated with it. Attributes describe the properties of the object, and operations allow you to create new objects and modify existing object attributes. See The Array Manager Storage Model section in the Storage Management Concepts chapter for more information about the Array Manager storage model.

Unless otherwise stated, each operation described in this chapter is available on each controller type listed above. Operations that are grayed out in the console are not supported or not available at that time. To view attributes or to perform operations, right-click on a given storage object. A context menu will appear with a list of commands available, including a Properties command.


Virtual Disk Configuration

Array Manager allows you to create virtual disks, which are logical disks that can be created from one or more physical disks (known as array disks). The logical disks can have RAID layouts, which let you to manage your storage more efficiently. Once a virtual disk is created and a rescan is done, the Windows® operating system sees the virtual disk as if it were a physical disk. The topics in this section include:

See also the section in this chapter on array disks, Array Disk Commands.

Creating Virtual Disks

Creating virtual disks is the first step in configuring your RAID storage subsystem. For more information about creating RAID solutions, see Choosing RAID Levels in the Storage Management Concepts chapter.

To create a virtual disk:
  1. Right-click on an array group and click Create Virtual Disk.

  2. Read the welcome screen shown and click Next to continue. (You can cancel the operation at any time by clicking the Cancel button.)

  3. The Select Creation Mode dialog box appears. Select Express or Custom Mode and click Next to continue or Back to return to the previous screen.

  4. Click Finish to create a virtual disk or Back to return to the previous screen.

  5. Rescan Disk Layout is checked by default because it is the recommended setting. Rescan Disk Layout allows the host operating system to recognize the new virtual disk and prepares the disk for use. If the Rescan Disk Layout box is not checked when you create the virtual disk, you can complete the same operation later by selecting the Rescan command.

Deleting Virtual Disks

Deleting a virtual disk permanently deletes all information contained within all volumes residing on that virtual disk.

CAUTION! All volumes and data on the virtual disk are lost when the disk is deleted.
To delete a virtual disk:

Use this procedure to delete a virtual disk on a PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller:

  1. Right-click on a virtual disk.

  2. Click Delete. A confirmation dialog box appears. Click Yes to continue.

Reconfiguring Virtual Disks

Use the Virtual Disk Reconfiguration wizard to change attributes of a virtual disk on a PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller. You can:

To reconfigure a virtual disk:

Use this procedure to reconfigure a virtual disk on a PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller:

  1. Right-click on a virtual disk to reconfigure and click Reconfigure.

  2. The Virtual Disk Reconfiguration window appears. Make the appropriate changes for the desired configuration.

  3. Click OK to continue or Cancel to quit the operation.


Virtual Disk Management

This section describes the following commands that are used to manage virtual disks:

Change Policy

Use this function to change the read and write cache policies of a virtual disk.

To change the read and write cache policies:
  1. Right-click on a virtual disk and click Change Policy.

  2. From the pull-down menus, enable or disable the cache policies and click OK.

The options are to enable or disable the write cache and to enable or disable the read cache.

  1. To verify your changes, right-click on the virtual disk, select Properties, and check the virtual disk properties.

Note: The "Write Cache" cache policy is not supported on the PERC 2/Si and 3/Si controllers.

Configure Hotspare

Use this operation to assign and configure a hot spare. This hot spare will be used to rebuild a degraded array disk, if possible.

If an array disk belonging to a virtual disk fails or is removed, the virtual disk will become degraded. A degraded virtual disk that has a properly configured hot spare will automatically rebuild onto that hot spare.

Note: This operation is highly recommended.
To configure a hot spare:
  1. Right-click on a redundant virtual disk and click Configure Hotspare.

  2. Assign the disks you want to configure as hot spares by dragging them from the left panel to the right panel and click OK.

Check Consistency

This operation verifies the accuracy of the redundant data in the virtual disk. You cannot check the consistency of a non-redundant RAID type.

To check consistency:
Note: It is recommended that you do not access any volumes on the virtual disk during the consistency check.

Format

Use this procedure to format a virtual disk on a PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller.

This operation erases the files and removes the file systems on virtual disks but keeps the virtual disk configuration intact.

To format:
Note: If you are formatting a virtual disk on a NetWare® system, you must first go to the NetWare console and remove the corresponding volume and partition. For information on how to perform these operations, see the appropriate NetWare documentation.

Restore Dead Disk Segments

This command recovers the disk space occupied by an orphan or dead disk segment. An orphan disk segment is part of a multipartition virtual disk that cannot access another disk segment within the same virtual disk. A dead disk segment is either no longer needed by the virtual disk or is physically damaged. This operation can be performed only on failed virtual disks of redundant RAID types.

To restore dead disk segments:
Note: You can restore only segments of a redundant RAID type.

Split Mirror

Use the Split Mirror command to permanently convert a mirror set or a multilevel virtual disk of mirror sets into two concatenated sets or two multilevel virtual disks of concatenated sets and preserve the data in each resulting virtual disk.

Note: This operation is not supported in NetWare.
To split a mirror:

Unmirror

Use the Unmirror command to convert the mirror set to a concatenated set or convert a multi-level virtual disk of mirror sets to a multilevel virtual disk of concatenated sets. Unmirroring preserves the data in the mirror set or multilevel virtual disk of mirror sets, but erases any data maintained by the redundant segment and returns the redundant virtual disk's segments to free space.

To unmirror:

CAUTION! Your virtual disk will no longer be redundant.

Properties

The Properties command brings up a screen that displays the properties of the virtual disk.


Array Group Commands

This section describes the commands available on the Array Group context menu. These commands are:

Create Virtual Disk

For more information about this command, see the section Creating Virtual Disks in this chapter.

RAID Policy

This command and the concepts associated with it are discussed in detail in the Policy-Based Storage Management chapter.

Properties

This command brings up a screen with the properties of the array group.


Array Disk Commands

This section describes Array Manager's commands for working with array disks. These commands are:

Note: A right-click on any one of the array disks displays a menu of supported operations. These menus are dynamic. Not all menu options are available at all times.

Diagnostics

Use this operation to verify that a disk is free from defects. This assures that the disk is safe to use as a member of a virtual disk.

Initialize Array Disks

The Initialize command prepares an array disk for use as a member of a virtual disk.

CAUTION! This is a data-destructive command. Any virtual disks residing on this array disk will be removed.

Format Array Disks

The Format command performs a low-level format on an array disk.

CAUTION! This is a data-destructive command. Any virtual disks residing on this array disk will be removed.

Remove Orphan/Dead Disk Segments

This command removes the disk space occupied by an orphan or dead disk segment.

A segment may be designated as dead if it is logically bad, is physically damaged, or resides on a disk that has been disconnected from and then reconnected to the controller.

Blink

The Blink command allows you to find an array disk within an enclosure by blinking one of the light-emitting diodes (LEDs) on the disk. This command will automatically cancel in 60 seconds.

Unblink

The Unblink command allows you to cancel the Blink command before the 60-second threshold has been reached.

Properties

Use this command to display the array disk properties.


PERC Subsystem Commands

The PERC subsystem has the following commands on its context menu:

View Report

This command allows you to view a report on the PERC 2 subsystem.

Save

This command allows you to save the controller configuration.

Properties

Use this command to view the properties of the PERC 2 subsystem.


General Controller Commands

This section describes the following controller commands and information on how to manage controller batteries:

Rescan Controller

The Rescan operation scans the channels of the controller to verify the currently connected devices or to recognize new devices that have been added to the channels.

To rescan the controller:
  1. Right-click on a controller.

  2. Click Rescan.

After the operation is finished, the console is refreshed and any configuration changes appear under the Array Group object and under the channel object.

The removal of an array disk within a virtual disk is reflected immediately in the console, whereas an addition is reflected only by performing the Rescan operation. Array disks that are not part of virtual disks will not be polled for status changes.

Pause I/O

This command pauses I/O on all channels that are polled for status changes on the controller. Use the Pause I/O command when you need to hot-swap disk drives without having to reboot.

If the disks are contained in an enclosure that supports hot-swapping, Pause I/O is not required unless the disk is part of a virtual disk.

CAUTION! This can be a potentially dangerous command, and sufficient steps should be taken to warn others who may be using any virtual disks on the selected controller that I/O will be paused.
To pause I/O:
  1. Right-click on a controller.

  2. Click Pause I/O.

The controller stays in this paused state for 150 seconds and then automatically resumes.

Initialize Array Disks

Use this function to initialize one or more array disks simultaneously. Array disks must be initialized before they can be used by Array Manager.

To initialize array disks:
  1. Right-click on a controller.

  2. Click Initialize Array Disks.

  3. Click OK after selecting which array disks you want to initialize.

Export Log File

This command extracts a log from the controller(s) and places it in the Array Manager installation directory. The log gives detailed information on the controller activities and can be useful for troubleshooting. The log's file name is the word "log" and the month and day, such as "log0921" for a log created on September 21.

Properties

Use this function to display controller attributes.

  1. Right-click on a controller.

  2. Click Properties.

Properties for each of PERC 2, PERC 2/Si, PERC 3/Si, and PERC 3/Di controllers appear differently. When a controller is opened in read-only mode, the console displays Read only in the name that appears in the left pane. If the controller is already in use, it can be opened only in read-only mode.

Note: A controller will be opened in Read Only mode if it is already in use.

Managing the Controller Battery

Note: The PERC 2/Si and PERC 3/Si RAID controllers do not contain a battery and therefore do not support battery management.

The battery of the PERC 2 controller preserves the contents of its nonvolatile cache memory in the event of power loss. The battery provides a minimum of 72 hours protection for DIMMs up to 64 MB and 48 hours protection for 128-MB DIMMs. However, the duration of protection, or holdover time, depends on the battery's charge level. This section has two topics:

Battery Recharging

The battery is fully discharged when you first install the controller. The controller detects this condition and automatically begins charging the battery. This charging process takes approximately three hours. The controller can be used during this time; however, the battery is unable to meet the specified holdover time until it is fully charged. The battery is still able to handle brief power losses during the initial charge cycle.

Battery Reconditioning

After you have installed the controller, it notifies you every six months that a battery reconditioning cycle is required. This reconditioning cycle requires a full discharge and recharge of the battery. It ensures that the battery's capacity is being measured correctly and that the battery's full holdover time is maintained.

To recondition the battery:
  1. Right-click on a controller.

  2. Click Properties.

  3. Click the Recondition button.

The reconditioning cycle takes approximately 8 to 10 hours. During this time, the battery's holdover time is reduced to zero (during discharge) and then restored (during full charge). To ensure that no data is lost from nonvolatile cache memory, the controller automatically disables cache (both read and write) during a reconditioning cycle. When the cache is disabled, performance is degraded for the reconditioning period. Once the reconditioning cycle is complete, the cache is restored to its original settings.

It is highly recommended that battery reconditioning be done during off-peak times.


General Channel Commands

This section describes the following general SCSI channel commands:

Rescan Channel

This operation can be used to rescan the channel to verify the connected devices or to check for devices that have been added.

  1. Right-click on a channel.

  2. Click Rescan.

Channel Properties

This operation displays channel attributes.

  1. Right-click on a channel.

  2. Click Properties. The Channel Properties dialog box appears.


Array Manager and FAST Compatibility Issues

Both Array Manager and FAST can be installed on the same server. However, only one program can be used to configure PERC 2, PERC 2/Si, PERC 3/Si, and PERC 3/Di controllers at any given time. These controller interfaces support two different access rights: read-only and read-write. To maintain the integrity of storage device configuration, these controllers grant only one application read-write access and all others read-only access.

When Array Manager is launched, it attempts to get read-write access. If read-write access is denied, then Array Manager gets read-only access. When Array Manager is launched in read-only mode, you can view storage devices and their properties but you cannot configure the PERC 2, PERC 2/Si, PERC 3/Si, and PERC 3/Di controllers or devices on them. Make sure FAST is not running if you want to launch Array Manager in read-write access mode.


Array and Volume Migration

After some planning and preparation, it is possible to migrate array disks, virtual disks, and array volumes between one controller and another, between one enclosure and another, or between one server and another. You can perform array and volume migration on PERC 2, PERC 2/Si, PERC 3/Si, and PERC 3/Di controllers as long as the following conditions are met:

  1. A virtual disk cannot be migrated from any PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di to any PERC 2/SC, PERC 2/DC or PERC 3/DCL controller.

  2. A virtual disk cannot be migrated from any PERC 2/SC, PERC 2/DC, or PERC 3/DCL controller to any PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di controller.

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To migrate virtual disks and volumes from one system to another, do the following.

  1. Right-click on the controller that contains the virtual disk(s) you are migrating and choose Pause I/O. You can also perform this operation with a shutdown of the server that contains the array disks and the virtual disk(s) that you wish to migrate.

  2. Remove the array disks from the enclosure that belong to the virtual disk(s) you are migrating, making sure to remember their order.

  3. Place the array disks into the new enclosure in the same order.

  4. Click Rescan on the Array Manager toolbar.


Naming Convention Differences

The terminology used in the Array Manager console differs from the terminology used in the PERC 2 BIOS Container Configuration Utility (CCU). The following table shows a summary of these differences.

Naming convention differences between Array Manager and PERC 2 BIOS Container Configuration Utility (CCU)

Array Manager

PERC 2 BIOS CCU

Virtual Disk

Container

Array Disk

Drive

Check Consistency

Scrub

Stripe Size

Chunk Size

Concatenation

Volume

Concatenation of RAID-1

Volume

RAID-0

RAID-0 (Stripe)

RAID-1

RAID-1 (Mirror)

Diagnostics

Verify


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