In order to implement RAID functions, RAID controllers must create a virtual disk. A virtual disk refers to storage created by a RAID controller from one or more array disks. Although a virtual disk may be created from several array disks, it is seen by the operating system as a single disk. Depending on the RAID level used, the virtual disk may retain redundant data in case of a disk failure or have particular performance attributes. See "Understanding Storage Concepts" for more information.

Note: Virtual disks can only be created on a RAID controller.

Considerations Before Creating Virtual Disks

Different controllers have particular characteristics in the way they implement virtual disks. These characteristics may include use of disk space, limitations on the number of virtual disks per controller, and so on. It can be helpful to understand these characteristics before creating virtual disks on the controller.

The following sections describe controller information that applies to virtual disks:

You may also wish to review the following sections:

Virtual Disk Considerations for PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers

In addition to the considerations described in this section, you should also be aware of the controller limitations described in "Number of Array Disks per Virtual Disk."

Be aware that the following considerations apply when creating virtual disks:

Creating virtual disks on PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers. When you create a virtual disk, you specify which array disks are to be included in the virtual disk. The virtual disk you create spans the specified array disks. Depending on the size of the virtual disk, the virtual disk may not consume all of the space on the array disks. Any leftover space on the array disks cannot be used for a second virtual disk unless the array disks are of equal size. In addition, when the array disks are of equal size and you can therefore use the leftover space for a second virtual disk, this new virtual disk cannot expand to include any array disks not included in the original virtual disk.
Space allocation when deleting and creating virtual disks on PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers. When you delete a virtual disk, you free up or make available space on the array disks that were being used by the deleted virtual disk. If you have created several virtual disks on an array group, then deleting virtual disks can result in pockets of free space residing in various locations on the array disks. When you create a new virtual disk, the controller must decide which free space on the array disks to allocate to the new virtual disk. The PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers look for the largest area of free space and allocate this space to the new virtual disk.
Deleting virtual disks on PERC 2/SC and 2/DC controllers. Due to hardware constraints, virtual disks on PERC 2/SC and 2/DC controllers must be deleted in reverse order of their creation. In other words, you must delete the most recently created virtual disk first and continue to delete in reverse order.
SCSI limitation of 2TB. Virtual disks created on a PERC 2/SC, 3/SC, 2/DC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, or CERC ATA100/4ch controller cannot be created from array disks with an aggregate size greater than 2TB. This is a limitation of the controller implementation. For example, you cannot select more than 30 array disks that are 73GB in size, regardless of the size of the resulting virtual disk. When attempting to select more than 30 disks of this size, a pop-up message is displayed that indicates that the 2TB limit has been reached, and that you should select a smaller number of array disks. The 2TB limit is an industry-wide SCSI limitation.
Expanding virtual disks. You can only use the Reconfigure task to expand a virtual disk that uses the full capacity of its member array disks. For more information, see Virtual Disk Task: Reconfigure (Step 1 of 3).
Virtual disk names not stored on controller. The names of the virtual disks that you create are not stored on the controller. This means that if you reboot using a different operating system, the new operating system may rename the virtual disk using its own naming conventions.
Creating and deleting virtual disks on cluster-enabled controllers. There are particular considerations for creating or deleting a virtual disk from a cluster-enabled controller. Review the Creating and Deleting Virtual Disks on Cluster-enabled Controllers section before attempting to create the virtual disk.
Requirements for using the entire capacity of an array disk on PERC 2/SC and 2/DC controllers. With PERC 2/SC and 2/DC controllers, it is recommended that whenever you create a virtual disk, you use the entire capacity of its member array disks. If you create a virtual disk that does not use all of the capacity of its member array disks, then the next virtual disk created must contain the remaining unused capacity of the array disks from which the previous virtual disk was created. When using RAID 10 and RAID 50, you can only create virtual disks that use the maximum capacity of the member array disks.
Implementing channel redundancy. A virtual disk is channel-redundant when it maintains redundant data on more than one channel. If one of the channels fails, data will not be lost because redundant data resides on another channel. For more information, see Channel Redundancy and Thermal Shutdown.
Rebuilding data. An failed array disk that is used by both redundant and non-redundant virtual disks cannot be rebuilt. Rebuilding a failed array disk in this situation requires deleting the non-redundant virtual disk.

Virtual Disk Considerations for PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers

When creating a virtual disk on a PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, or CERC SATA1.5/2s controller, the array disk selection has implications for how effectively a hot spare can rebuild the virtual disk. See "Understanding Hot Spares" and Considerations for Hot Spares on PERC 2, 2/Si, 3/Si, 3/Di, and CERC SATA1.5/6ch Controllers for more information.

Number of Array Disks per Virtual Disk

This section applies to PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, CERC ATA100/4ch, PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers

There are limitations on the number of array disks that can be included in the virtual disk. These limitations depend on the controller. When creating a virtual disk, controllers support a certain number of stripes and spans (methods for combining the storage on array disks). Because the number of total stripes and spans is limited, the number of array disks that can be used is also limited. The limitations on stripes and spans affect the possibilities for concatenation and RAID levels as follows:

Maximum number of spans affects concatenation, RAID Level 1-Concatenated, RAID 10 and RAID 50.
Maximum number of stripes affects RAID 0, RAID 5, and RAID 50.
Number of array disks in a mirror is always 2. This affects RAID 1, RAID Level 1-Concatenated, and RAID 10.

In the case of RAID 50, you can use a greater number of array disks than is possible for the other RAID levels. The number of channels on the controller, however, imposes limitations on how many array disks can be included in a virtual disk when using RAID 50. This is because only a limited number of array disks can be physically attached to the controller.

Number of Array Disks per Virtual Disk for PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers

The following table describes the specific limitations for the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers.

Number of Array Disks per Virtual Disk

Concatenation or RAID Level

PERC 2/SC and 2/DC

PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di

CERC ATA100/4ch

Concatenation
2 to 8
2 to 8
2 to 4

RAID 0
1 to 8
1 to 32
1 to 4

RAID 1
2
2
2

RAID 5
3 to 8
3 to 32
3 or 4

RAID 10
An even number from 2 to 16
An even number from 2 to 16
4

RAID 50
Between 6 and the number of array disks attached to the controller. For example, if 14 array disks are attached to a 2/SC controller, then the allowable number of array disks included in a virtual disk on this controller is between 6 and 14.
A prime number of array disks is not allowed in a RAID 50 array for these controllers. For example, the following prime numbers are excluded: 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 51, and 53.
Not supported

Number of Array Disks per Virtual Disk
Concatenation or RAID Level	PERC 2/SC and 2/DC	PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di	CERC ATA100/4ch
Concatenation	2 to 8	2 to 8	2 to 4
RAID 0	1 to 8	1 to 32	1 to 4
RAID 1	2	2	2
RAID 5	3 to 8	3 to 32	3 or 4
RAID 10	An even number from 2 to 16	An even number from 2 to 16	4
RAID 50	Between 6 and the number of array disks attached to the controller. For example, if 14 array disks are attached to a 2/SC controller, then the allowable number of array disks included in a virtual disk on this controller is between 6 and 14. A prime number of array disks is not allowed in a RAID 50 array for these controllers. For example, the following prime numbers are excluded: 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 51, and 53.	Not supported

Number of Array Disks per Virtual Disk on PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s Controllers

The following table describes the specific limitations for the PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers.

Number of Array Disks per Virtual Disk

Concatenation or RAID Level

PERC 2, 2/Si, 3/Si, and 3/Di

CERC SATA1.5/6ch

CERC SATA1.5/2s

Concatenation
1
1
1

RAID 0
1 to 32
1 to 32
2

RAID 1
2
2
2

RAID 5
3 to 16
3 to 16
N/A

RAID Level 1-Concatenated (Concatenated Mirror)
An even number from 4 to 32
N/A
N/A

RAID 10
4 to 32
4 to 32
N/A

Number of Array Disks per Virtual Disk
Concatenation or RAID Level	PERC 2, 2/Si, 3/Si, and 3/Di	CERC SATA1.5/6ch	CERC SATA1.5/2s
Concatenation	1	1	1
RAID 0	1 to 32	1 to 32	2
RAID 1	2	2	2
RAID 5	3 to 16	3 to 16	N/A
RAID Level 1-Concatenated (Concatenated Mirror)	An even number from 4 to 32	N/A	N/A
RAID 10	4 to 32	4 to 32	N/A

For more information on storage concepts used in this section, see What Is RAID? and Choosing RAID Levels and Concatenation.

Note: In addition to this online help, you should review the hardware documentation that is provided with the controllers. Reviewing the hardware documentation along with this online help may provide a fuller understanding of the controller limitations.

Maximum Virtual Disks on PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers

You can create a maximum of 8 virtual disks on one PERC 2/SC or PERC 2/DC controller and a maximum of 40 virtual disks on one CERC ATA100/4ch controller. On the PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, and 4e/Di controllers, you can create a maximum of 40 virtual disks.

Maximum Virtual Disks on PERC 2, PERC 2/Si, PERC 3/Si, or PERC 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s Controllers

You can create a maximum of 24 virtual disks on a PERC 2, PERC 2/Si, PERC 3/Si, PERC 3/Di, and CERC SATA1.5/6ch. However, each array disk on these controllers can only be used for up to ten virtual disks.

The CERC SATA1.5/2s controller only allows for one virtual disk when using RAID 0 and RAID 1 and up to two virtual disks when using concatenation.

Channel Redundant Virtual Disks

When creating a virtual disk, it is possible to use disks attached to different channels to implement channel redundancy. This configuration might be used for disks that reside in enclosures subject to thermal shutdown. See the following for more information:

Note: Channel redundancy only applies to controllers that have more than one channel and that attach to an external disk enclosure.

Creating Virtual Disks

This section applies to PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch, PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers

In order to implement RAID functions, you need to create a virtual disk. A virtual disk refers to storage created by a RAID controller from one or more array disks. Although a virtual disk may be created from several array disks, it is seen by the operating system as a single disk. See "What Is RAID?" for more information.

Before creating a virtual disk, you should be familiar with the information in the Considerations Before Creating Virtual Disks section.

Storage Management provides wizards to help you create a virtual disk:

The Create Virtual Disk Express Wizard calculates an appropriate virtual disk layout based on the available space and controller considerations. Using the Express Wizard, you can quickly create a virtual disk using recommended selections. See Create Virtual Disk Express Wizard (Step 1 of 2) for more information.
The Create Virtual Disk Advanced Wizard allows you to specify the read, write, and cache policy for the virtual disk. You can also select the array disks and the controller channel to be used. You need a good knowledge of RAID levels and hardware to use the Advanced Wizard. See Create Virtual Disk Advanced Wizard (Step 1 of 4) for more information.

You may also wish to refer to the following related sections:

What Is RAID? in the Understanding Storage Concepts chapter.
Channel Redundancy and Thermal Shutdown for information on creating a channel-redundant virtual disk
Virtual Disk Task: Delete
Reconfiguring/Migrating Virtual Disks
Array and Hard Disk Properties and Tasks

Reconfiguring/Migrating Virtual Disks

This section applies to PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, CERC ATA100/4ch, PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers

You can reconfigure or migrate a virtual disk in order to increase the disks capacity or change its RAID level.

To reconfigure a virtual disk:

Review the information in Starting and Target RAID Levels for Virtual Disk Reconfiguration.
Locate the controller on which the virtual disk resides in the tree view. Expand the Controller object until the Virtual Disk object is displayed.
Select the Reconfigure task from the virtual disk's drop-down menu and click Execute.
Complete the Reconfigure task using the Reconfigure wizard. See Virtual Disk Task: Reconfigure (Step 1 of 3) for more information.

Starting and Target RAID Levels for Virtual Disk Reconfiguration

Once you have created a virtual disk, the possibilities for reconfiguring the virtual disk depend on the controller, RAID level, and available array disks. The following table describes the possible scenarios for reconfiguring a virtual disk. For more information on the RAID levels, see Choosing RAID Levels and Concatenation.

Virtual Disk Reconfiguration

Controller

Starting RAID Level

Target RAID Level

Comments

PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, PERC 4/DC, PERC 4e/DC, 4/Di, 4e/Si, PERC 4e/Di, CERC ATA100/4ch
RAID 0 (on a single disk)
RAID 1
Add a single disk

RAID 0
RAID 5
With or without adding additional disks

RAID 1
RAID 0
With or without adding additional disks

RAID 1
RAID 5
Add additional disks

RAID 5
RAID 0
With or without adding additional disks

RAID 5
RAID 5
Add additional disks

PERC 4/IM
N/A
N/A
N/A

PERC 2, 2/Si, 3/Si, and 3/Di
Concatenation
RAID 1
Minimum number of array disks required for the target RAID level must be available

RAID 0
RAID 0, RAID 5, RAID 10, RAID 1-concatenated

RAID 1
RAID 0, RAID 1, RAID 5, RAID 10, RAID 1-concatenated

RAID 5
RAID 0, RAID 5, RAID 10

RAID 10
RAID 0, RAID 5, RAID 10

RAID 1-concatenated
RAID 1-concatenated

CERC SATA1.5/6ch
Concatenation
RAID 1
Minimum number of array disks required for the target RAID level must be available

RAID 0
RAID 0, RAID 5, RAID 10

RAID 1
RAID 0, RAID 1, RAID 5, RAID 10

RAID 5
RAID 0, RAID 5, RAID 10

RAID 10
RAID 0, RAID 5, RAID 10

CERC SATA1.5/2s
N/A
N/A
N/A

	Virtual Disk Reconfiguration
Controller	Starting RAID Level	Target RAID Level	Comments
PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, PERC 4/DC, PERC 4e/DC, 4/Di, 4e/Si, PERC 4e/Di, CERC ATA100/4ch	RAID 0 (on a single disk)	RAID 1	Add a single disk
RAID 0	RAID 5	With or without adding additional disks
RAID 1	RAID 0	With or without adding additional disks
RAID 1	RAID 5	Add additional disks
RAID 5	RAID 0	With or without adding additional disks
RAID 5	RAID 5	Add additional disks
PERC 4/IM	N/A	N/A	N/A
PERC 2, 2/Si, 3/Si, and 3/Di	Concatenation	RAID 1	Minimum number of array disks required for the target RAID level must be available
RAID 0	RAID 0, RAID 5, RAID 10, RAID 1-concatenated
RAID 1	RAID 0, RAID 1, RAID 5, RAID 10, RAID 1-concatenated
RAID 5	RAID 0, RAID 5, RAID 10
RAID 10	RAID 0, RAID 5, RAID 10
RAID 1-concatenated	RAID 1-concatenated
CERC SATA1.5/6ch	Concatenation	RAID 1	Minimum number of array disks required for the target RAID level must be available
	RAID 0	RAID 0, RAID 5, RAID 10
	RAID 1	RAID 0, RAID 1, RAID 5, RAID 10
	RAID 5	RAID 0, RAID 5, RAID 10
	RAID 10	RAID 0, RAID 5, RAID 10
CERC SATA1.5/2s	N/A	N/A	N/A

Maintain Integrity of Redundant Virtual Disks

The virtual disk Check Consistency task verifies the accuracy of the redundant (parity) information. This task only applies to redundant virtual disks. When necessary, the Check Consistency task rebuilds the redundant data.

To verify a virtual disk's redundant information:

Locate the controller on which the virtual disk resides in the tree view. Expand the Controller object until the Virtual Disk object is displayed.
Select the Check Consistency task from the virtual disk's drop-down menu and click Execute.

Rebuilding Redundant Information

This section applies to PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, CERC ATA100/4ch, PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers

If you have a redundant virtual disk, you can reconstruct the contents of a failed array disk onto a new disk or a hot spare. A rebuild can take place during normal operation, but it will degrade performance. The following sections provide additional information on rebuilding disks.

Replacing a Failed Disk describes how to replace a failed array disk and initiate a rebuild.
Set Rebuild Rate describes how to set the rebuild rate on selected controllers.
Rebuild Does Not Work describes situations in which a rebuild will not work.

Virtual Disk Properties and Tasks

Use this window to view information about the virtual disks and execute virtual disk tasks.

Virtual Disk Properties

The virtual disk properties can vary depending on the model of the controller. Virtual disk properties may include:

Property

Definition

Status

These icons represent the severity or health of the storage component. See Storage Component Severity for more information.

Name
This property displays the virtual disk name.

State
This property displays the current status of the virtual disk. Possible values are:
Ready — The virtual disk is functioning normally.

Degraded — The virtual disk has suffered a failure of a component and is operating in a degraded state.

Resynching — A consistency check or reconfiguration is being performed on the virtual disk.

Failed — The virtual disk has suffered a failure of one or more components and is no longer functioning.

Failed Redundancy Failing — The virtual disk has lost redundancy due to a drive failure. An additional drive in the virtual disk is receiving S.M.A.R.T. alerts and may fail, causing data loss.

Background Initialization — A background initialization is being performed on the virtual disk.

Formatting — The virtual disk is being formatted. Formatting applies to the PERC 2, 2/Si, 3/Si, 3/Di, and CERC SATA1.5/6ch controllers. See Format or Initialize for more information.

Initializing — The virtual disk is being initialized. Initialization applies to the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers. See Format or Initialize for more information.

Note: On some controllers, the virtual disk state is not updated until the controller performs an I/O operation. See I/O Requirements for Detecting Drive Status Changes for more information.

Device Name
This property displays the operating system device name for this object.

Read Policy
This property displays the read policy that the controller is using for this virtual disk. See RAID Controller Read, Write, and Cache Policy.

Write Policy
This property displays the write policy that the controller is using for this virtual disk. See RAID Controller Read, Write, and Cache Policy.

Cache Policy
This property displays the cache policy that the controller is using for this virtual disk. See RAID Controller Read, Write, and Cache Policy.

Layout
This property displays the RAID level.

Size
This property displays the total capacity of the virtual disk.

Note: The algorithm for calculating the virtual disk size rounds a value of 0.005 or less down to 0.00 and a value between 0.006 and 0.009 up to 0.01. For example, a virtual disk size of 819.725 will be rounded down to 819.72. A virtual disk size of 819.726 will be rounded up to 819.73.

Stripe Size
This property displays the stripe size of the virtual disk.

Virtual Disk Tasks

Do the following to execute a virtual disk drop-down menu task:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Select a task from the Available Tasks drop-down menu.
Click Execute.

Note: Different controllers support different features. For this reason, the tasks displayed on the Tasks drop-down menu can vary depending on which controller is selected in the tree view.

Virtual Disk Drop-down Menu Tasks:

Reconfigure

Use the Reconfigure task to change the virtual disks properties. For example, you can use this task to add array disks or change the RAID level. See Virtual Disk Task: Reconfigure (Step 1 of 3) for more information.

Format or Initialize

Use the Format or Initialize task to erase the files and remove the file systems on a virtual disk. Some controllers require that you initialize a virtual disk before it can be used. See Format or Initialize for more information.

Cancel Background Initialization

On PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers, background initialization of redundant virtual disks begins automatically after the virtual disk is created. Because the initialization is run in the background, other processes can continue while the initialization completes.

The background initialization of a redundant virtual disk prepares the virtual disk for parity information and improves write performance. It is important that the background initialization be allowed to run to completion. You can, however, cancel the background initialization. When you do so, the controller will restart the background initialization at a later time. See Background Initialization on PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers for more information.

Use the Cancel Background Initialization task to cancel the virtual disk initialization.

Note: On the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers, the controller firmware uses the rebuild rate setting to control the system resource allocation for the Background Initialization task. See Set Rebuild Rate for more information.

Restore Dead Segments

Use the Restore Dead Segments task to recover data from a RAID-5 virtual disk that has been corrupted. The Restore Dead Segments task attempts to reconstruct data from a corrupt portion of an array disk included in a RAID-5 virtual disk. The Restore Dead Segments task uses the parity or redundant information to reconstruct the lost data. This task is not always able to recover lost data.

Delete

Use the Delete task to destroy all data on the virtual disk. See Virtual Disk Task: Delete for more information.

Assign and Unassign Dedicated Hot Spare

Use the Assign Dedicated Hot Spare task to assign a disk as a backup for a single virtual disk. See Assign and Unassign Dedicated Hot Spare for more information.

Check Consistency

Use the Check Consistency task to verify the accuracy of the redundant (parity) information. This task only applies to redundant virtual disks. When necessary, the Check Consistency task rebuilds the redundant data. If the virtual disk has a Degraded status, running a check consistency may be able to return the virtual disk to Ready status.

Note: On the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers, the controller firmware uses the rebuild rate setting to control the system resource allocation for the Check Consistency task. See Set Rebuild Rate for more information.

Cancel Check Consistency

Use the Cancel Check Consistency task to stop a check consistency operation that is in progress.

Pause Check Consistency

Use the Pause Check Consistency task to pause a check consistency while it is in progress.

Resume Check Consistency

Use the Resume Check Consistency task to resume a check consistency after it has been paused.

Blink and Unblink

The Blink and Unblink tasks blink or unblink the lights on the array disks included in the virtual disk. See Blink and Unblink for more information.

Rename

Use the Rename task to change the virtual disk's name. See Virtual Disk Task: Rename for more information.

Note: On the CERC SATA1.5/2s controller, you cannot change the default name of a concatenated virtual disk.

Change Policy

Use the Change Policy task to change a virtual disk's read, write, or cache policy. See RAID Controller Read, Write, and Cache Policy for more information.

Create Virtual Disk Express Wizard (Step 1 of 2)

The Create Virtual Disk Express Wizard calculates an appropriate virtual disk configuration based on the available space and controller considerations. When using the Express Wizard, you select the RAID level and size for the virtual disk. The wizard selects a recommended disk configuration for you that matches your RAID and size selection.

Before creating a virtual disk, you should be familiar with the information in Considerations Before Creating Virtual Disks. You may also wish to review Choosing RAID Levels and Concatenation.

If you wish to make your own selections for the virtual disk configuration, click Go To Advanced Wizard.

To Create a Virtual Disk Express Wizard: Step 1 of 2

Click the radio button to select the correct RAID level.
- Depending on the controller, Concatenated enables you to combine the storage capacity of several disks or to create a virtual disk using only a single array disk. See Number of Array Disks per Virtual Disk for information on whether the controller supports a single array disk or two or more when using Concatenated. Using Concatenated does not provide data redundancy nor does it affect the read and write performance.
- Select RAID 0 for striping. This selection groups n disks together as one large virtual disk with a total capacity of n disks. Data is stored to the disks alternately so that they are evenly distributed. Data redundancy is not available in this mode. Read and write performance is enhanced.
- Select RAID 1 for mirroring disks. This selection groups two disks together as one virtual disk with a capacity of one single disk. The data is replicated on both disks. When a disk fails, the virtual disk continues to function. This feature provides data redundancy and good read performance, but slightly slower write performance. Your system must have at least two disks to use RAID 1.
- Select RAID 1-concatenated to span a RAID 1 array across more than a single pair of array disks. RAID 1-concatenated combines the advantages of concatenation with the redundancy of RAID 1. No striping is involved in this RAID type.
- Select RAID 5 for striping with distributed parity. This selection groups n disks together as one large virtual disk with a total capacity of (n-1) disks. When a disk fails, the virtual disk continues to function. This feature provides better data redundancy and read performance, but slower write performance. Your system must have at least three disks to use RAID 5.
- Select RAID 10 for striping over mirror sets. This selection groups n disks together as one large virtual disk with a total capacity of (n/2) disks. Data is striped across the replicated mirrored pair disks. When a disk fails, the virtual disk continues to function. The data is read from the surviving mirrored pair disk. This feature provides the best failure protection, read and write performance. Your system must have at least four disks to use RAID 10.
- Select RAID 50 to implement striping across more than one three-drive span. RAID 50 groups n*s disks as one large virtual disk with a capacity of s*(n-1) disks, where s is the number of spans and n is the number of disks within each span.
Type a name for the virtual disk in the Name text box.

The virtual disk name can contain only alphanumeric characters as well as spaces, dashes and underscores. The maximum name length depends on the controller. In most cases, the maximum length is 15 characters. The name cannot start with a space or end with a space.

It is recommended that you specify a unique name for each virtual disk. If you have virtual disks with the same name, it will be hard to differentiate the alerts generated for these virtual disks.

Note: The CERC SATA1.5/2s controller does not allow you to specify a name for concatenated virtual disks. The concatenated virtual disk will be created with a default name.

Type the size for the virtual disk in the Size text box. The virtual disk size must be within the minimum and maximum values displayed near the Size text box. In some cases, the virtual will be slightly larger than the size you specify. The Create Virtual Disk wizard may round up the size of the virtual disk to avoid rendering a portion of the array disk space unusable.

Note: When creating a virtual disk on the CERC SATA1.5/2s controller, you must specify the maximum virtual disk size.

Click Continue to go to the next screen or Exit Wizard if you wish to cancel.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Click Go To Create Virtual Disk Wizard.

Create Virtual Disk Express Wizard (Step 2 of 2)

This screen displays the attributes for the virtual disk you are creating. The selections you made using Create Virtual Disk Express Wizard (Step 1 of 2) are displayed on this screen. The array disks that the Express Wizard selected are also displayed on this screen.

Do one of the following:

Click Finish to create the virtual disk with the attributes shown on this screen.
Click Go Back To Previous Page to return to Create Virtual Disk Express Wizard (Step 1 of 2) if you wish to change your selections.
Click Exit Wizard to cancel the virtual disk.

Create Virtual Disk Advanced Wizard (Step 1 of 4)

The Create Virtual Disk Advanced Wizard allows you to specify the read, write, and cache policy for the virtual disk. You can also select the array disks and the controller channel to be used. You need a good knowledge of RAID levels and hardware to use the Advanced Wizard.

Before creating a virtual disk, you should be familiar with the information in Considerations Before Creating Virtual Disks. You may also wish to review Choosing RAID Levels and Concatenation.

If you wish to have the wizard choose a recommended virtual disk configuration for you, click Go To Express Wizard.

To Create a Virtual Disk Advanced Wizard: Step 1 of 4

Click the radio button to select the correct RAID level.
- Depending on the controller, Concatenated enables you to combine the storage capacity of several disks or to create a virtual disk using only a single array disk. See Number of Array Disks per Virtual Disk for information on whether the controller supports a single array disk or two or more when using Concatenated. Using Concatenated does not provide data redundancy nor does it affect the read and write performance.
- Select RAID 0 for striping. This selection groups n disks together as one large virtual disk with a total capacity of n disks. Data is stored to the disks alternately so that they are evenly distributed. Data redundancy is not available in this mode. Read and write performance is enhanced.
- Select RAID 1 for mirroring disks. This selection groups two disks together as one virtual disk with a capacity of one single disk. The data is replicated on both disks. When a disk fails, the virtual disk continues to function. This feature provides data redundancy and good read performance, but slightly slower write performance. Your system must have at least two disks to use RAID 1.
- Select RAID 1-concatenated to span a RAID 1 array across more than a single pair of array disks. RAID 1-concatenated combines the advantages of concatenation with the redundancy of RAID 1. No striping is involved in this RAID type.
- Select RAID 5 for striping with distributed parity. This selection groups n disks together as one large virtual disk with a total capacity of (n-1) disks. When a disk fails, the virtual disk continues to function. This feature provides better data redundancy and read performance, but slower write performance. Your system must have at least three disks to use RAID 5.
- Select RAID 10 for striping over mirror sets. This selection groups n disks together as one large virtual disk with a total capacity of (n/2) disks. Data is striped across the replicated mirrored pair disks. When a disk fails, the virtual disk continues to function. The data is read from the surviving mirrored pair disk. This feature provides the best failure protection, read and write performance. Your system must have at least four disks to use RAID 10.
- Select RAID 50 to implement striping across more than one three-drive span. RAID 50 groups n*s disks as one large virtual disk with a capacity of s*(n-1) disks, where s is the number of spans and n is the number of disks within each span.
Click Continue to go to the next screen or Exit Wizard if you wish to cancel.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Click Go To Create Virtual Disk Wizard.
Click Go To Advanced Wizard.

Create Virtual Disk Advanced Wizard (Step 2 of 4)

This screen enables you to select which disks will be used to create the virtual disk. The items displayed on this screen depend on the selections you made in Create Virtual Disk Advanced Wizard (Step 1 of 4).

Note: For a controller that has more than one channel, it may be possible to configure a virtual disk that is channel-redundant. See Channel Redundancy and Thermal Shutdown for more information.

Depending on the RAID level you selected and the virtual disk size, this screen displays the disks and channels available for configuring the virtual disk.

The following is an example of what might be displayed:

Channel 0

The Channel section of the screen displays the controller's channels and the disks attached to each channel. Select the disks to be included in the virtual disk. In this example, the controller has a single channel with five disks.

Array Disk 0:0
Array Disk 0:1
Array Disk 0:2
Array Disk 0:3
Array Disk 0:4

Array Disks Selected

The Array Disks Selected section of the screen displays the disks you have chosen. In this example, two disks are selected.

Array Disk 0:0
Array Disk 0:1

Each RAID level has specific requirements for the number of disks that must be selected. RAID 10 and 50 also have requirements for how many disks are included in each stripe or span. If you click Continue before you have made the proper selection, a pop-up message displays additional information for correcting your choice.

Click Continue when you have completed the disk selection. If you wish to cancel the virtual disk, click Exit Wizard. If you wish to return to the previous screen and change your selections, click Go Back To Previous Page.

Create Virtual Disk Advanced Wizard (Step 3 of 4)

This screen enables you to select attributes for the virtual disk. These attributes include the name, size and read, write, and cache policy. Depending on the controller and your previous virtual disk selections, the items displayed on this screen can vary.

Do the following:

Type the name of the virtual disk in the Name text box.

It is recommended that you specify a unique name for each virtual disk. If you have virtual disks with the same name, it will be hard to differentiate the alerts generated for these virtual disks.

Note: The CERC SATA1.5/2s controller does not allow you to specify a name for concatenated virtual disks. The concatenated virtual disk will be created with a default name.

The Size text box displays the default size of the virtual disk, depending upon the RAID configuration you selected. You can specify a different size. The virtual disk size must be within the minimum and maximum values displayed near the Size text box. In some cases, the virtual will be slightly larger than the size you specify. The Create Virtual Disk wizard may round up the size of the virtual disk to avoid rendering a portion of the array disk space unusable.

Note: When creating a virtual disk on the CERC SATA1.5/2s controller, you must specify the maximum virtual disk size.

Select a stripe size from the Stripe Size drop-down menu. The stripe size refers to the amount of space that each stripe consumes on a single disk. See What Is RAID? for more information.
Select the read, write, and cache policy. These selections can vary depending on the controller. See RAID Controller Read, Write, and Cache Policy for more information.

Note: Read, write, and cache policies are not supported on the CERC SATA1.5/2s controller.

Click Continue to go to the next screen If you wish to cancel the virtual disk, click Exit Wizard. If you wish to return to the previous screen and change your selections, click Go Back To Previous Page.

Create Virtual Disk Advanced Wizard (Step 4 of 4)

This screen displays the attributes for the virtual disk you are creating. The selections you made previously are displayed on this screen.

Do one of the following:

Click Finish to create the virtual disk with the attributes shown on this screen.
Click Go Back To Previous Page to return to Create Virtual Disk Advanced Wizard (Step 3 of 4) if you wish to change your selections.
Click Exit Wizard to cancel the virtual disk.

Virtual Disk Task: Reconfigure (Step 1 of 3)

The Reconfigure task enables you to change the virtual disk configuration. Using this task, you can change the RAID level and increase the virtual disk size by adding array disks. On some controllers, you can also remove array disks.

Before continuing with the virtual disk reconfiguration, you should be familiar with the information in Starting and Target RAID Levels for Virtual Disk Reconfiguration and Choosing RAID Levels and Concatenation.

To Reconfigure a Virtual Disk: Step 1 of 3

Select the array disks that you want to include in the virtual disk. You can expand the virtual disk's capacity by adding additional array disks. On some controllers, you can also remove array disks.

The changes you make to the array disk selection are displayed in the Selected Array Disks table.

Note: For a controller that has more than one channel, it may be possible to configure a virtual disk that is channel-redundant. See Channel Redundancy and Thermal Shutdown for more information.

Click Continue to go to the next screen or Exit Wizard if you wish to cancel.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Select Reconfigure from the Available Tasks drop-down menu.
Click Execute.

Virtual Disk Task: Reconfigure (Step 2 of 3)

This screen enables you to select the RAID level and size for the reconfigured virtual disk.

To Reconfigure a Virtual Disk: Step 2 of 3

Select the new RAID level for the virtual disk. The available RAID levels depend on the number or array disks selected and the controller. The following describes possible RAID levels:
- Depending on the controller, Concatenated enables you to combine the storage capacity of several disks or to create a virtual disk using only a single array disk. See Number of Array Disks per Virtual Disk for information on whether the controller supports a single array disk or two or more when using Concatenated. Using Concatenated does not provide data redundancy nor does it affect the read and write performance.
- Select RAID 0 for striping. This selection groups n disks together as one large virtual disk with a total capacity of n disks. Data is stored to the disks alternately so that they are evenly distributed. Data redundancy is not available in this mode. Read and write performance is enhanced.
- Select RAID 1 for mirroring disks. This selection groups two disks together as one virtual disk with a capacity of one single disk. The data is replicated on both disks. When a disk fails, the virtual disk continues to function. This feature provides data redundancy and good read performance, but slightly slower write performance. Your system must have at least two disks to use RAID 1.
- Select RAID 1-concatenated to span a RAID 1 array across more than a single pair of array disks. RAID 1-concatenated combines the advantages of concatenation with the redundancy of RAID 1. No striping is involved in this RAID type.
- Select RAID 5 for striping with distributed parity. This selection groups n disks together as one large virtual disk with a total capacity of (n-1) disks. When a disk fails, the virtual disk continues to function. This feature provides better data redundancy and read performance, but slower write performance. Your system must have at least three disks to use RAID 5.
- Select RAID 10 for striping over mirror sets. This selection groups n disks together as one large virtual disk with a total capacity of (n/2) disks. Data is striped across the replicated mirrored pair disks. When a disk fails, the virtual disk continues to function. The data is read from the surviving mirrored pair disk. This feature provides the best failure protection, read and write performance. Your system must have at least four disks to use RAID 10.
Type the size for the reconfigured virtual disk in the Size text box. The minimum and maximum allowable size is displayed under the Size text box. These values reflect the new capacity of the virtual disk after any addition or deletion of array disks which you may have chosen in Virtual Disk Task: Reconfigure (Step 1 of 3).

Note: On the CERC SATA1.5/2s controller, you must specify the maximum virtual disk size.

Click Continue to go to the next screen or Exit Wizard if you wish to cancel.

Virtual Disk Task: Reconfigure (Step 3 of 3)

This screen enables you to review your changes before completing the virtual disk reconfiguration.

To Reconfigure a Virtual Disk: Step 3 of 3

Review your changes. The New Virtual Disk Configuration table displays the changes you have made to the virtual disk. The Previous Virtual Disk Configuration displays the original virtual disk prior to reconfiguration.
Click Finish to complete the virtual disk reconfiguration. If you wish to exit without changing the original virtual disk, click Exit Wizard.

Note: On some controllers, performing a Rescan while a reconfiguration is in progress will cause the virtual disk configuration and the array disk state to display incorrectly. For example, changes to the virtual disk's RAID level may not be displayed and the state of array disks that were added to the virtual disk may display as Ready instead of Online.

Format or Initialize

The Format or Initialize task erases the files and removes the file systems on virtual disks while keeping the virtual disk configuration intact. Formatting or initializing a virtual disk destroys all data on the virtual disk. If the boot partition resides on the virtual disk, it will be destroyed by the format operation.

Note: On a Linux system, you cannot format a virtual disk that contains a mounted volume.

Considerations for PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers

The initialize task applies to the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers.

These controllers also have a background initialization feature. For more information, see Background Initialization on PERC 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers.

Note: A fast initialization on the PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers may occur so quickly that the virtual disk's State does not display Initializing. Use the controller BIOS to change the initialization settings.

Considerations for PERC 2, 2/Si, 3/Si, 3/Di, and CERC SATA1.5/6ch Controllers

The format task applies to the PERC 2, 2/Si, 3/Si, 3/Di, and CERC SATA1.5/6ch controllers.

To Format or Initialize a Disk:

Review the virtual disk that will be destroyed by the Format or Initialize and make sure that vital data will not be lost. Click Blink at the bottom of the screen to blink the array disks included in the virtual disk.
Click Format or Initialize when you are ready. To exit without formatting or initializing the virtual disk, click Go Back To Virtual Disk Page.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Select Format or Initialize from the Available Tasks drop-down menu.
Click Execute.

Virtual Disk Task: Delete

Deleting a virtual disk destroys all information including file systems and volumes residing on the virtual disk.

To delete a virtual disk:

To identify which array disks are included in the virtual disk, click Blink. The LED lights on the array disks will blink for 30 to 60 seconds.

When deleting a virtual disk, the following considerations apply:

Because of PERC 2/SC and 2/DC controller hardware constraints, virtual disks must be deleted in the reverse order of their creation on these controllers. In other words, the last disk that you created must be deleted first.
There are particular considerations for deleting a virtual disk from a cluster-enabled controller. Review the Creating and Deleting Virtual Disks on Cluster-enabled Controllers before attempting to delete the virtual disk.
It is recommended that you reboot the system after deleting the virtual disk. Rebooting the system ensures that the operating system recognizes the disk configuration correctly.
If you delete a virtual disk and immediately create a new virtual disk with all the same characteristics as the one that was deleted, the controller will recognize the data as if the first virtual disk were never deleted. In this situation, if you don't want the old data after recreating a new virtual disk, reinitialize the virtual disk.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Select Delete from the Available Tasks drop-down menu.
Click Execute.

Virtual Disk Task: Rename

Renaming a virtual disk enables you to change the virtual disk's name. The numbering format for the virtual disk remains unchanged.

Depending on the controller you have, there are different considerations regarding the controller BIOS:

On PERC 2/SC, 2/DC, 3/SC, 3/DCL, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4/IM, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers, changing the virtual disk name with Storage Management does not change the name in the BIOS.
On PERC 2, 2/Si, 3/Si, 3/Di, CERC SATA1.5/6ch, and CERC SATA1.5/2s controllers, changing the virtual disk name with Storage Management also changes the name in the BIOS. If you do not specify a name for a virtual disk (either when you create the virtual disk or by using the Rename task) then the name for the virtual disk in the BIOS will be "Virtual Disk".
The virtual disk name can contain only alphanumeric characters as well as spaces, dashes and underscores. The maximum name length depends on the controller. In most cases, the maximum length is 15 characters. The name cannot start with a space, end with a space, or be left blank.

Note The Rename task is not available for concatenated virtual disks on a CERC SATA1.5/2s controller.

To rename a virtual disk:

Type the new name in the text box.
Click Rename. If you want to exit without renaming the virtual disk, click Go Back To Virtual Disk Page.

To locate this task in Storage Management:

Expand the Storage tree object to display the controller objects.
Expand a controller object.
Select the Virtual Disks object.
Select Rename from the Available Tasks drop-down menu.
Click Execute.

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