This command creates a RAID logical drive with the given properties without initializing any of the user data areas on the disk drives. Parameter values are derived from the Recovery Profile data file for the storage subsystem.
recover logicalDrive (drive=(enclosureID,slotID) | drives=(enclosureID1,slotID1 ... enclosureIDn,slotIDn) | array=arrayName) [newArray=arrayName] userLabel=”logicalDriveName” capacity=logicalDriveCapacity offset=offsetValue raidLevel=(0 | 1 | 3 | 5 | 6) segmentSize=segmentSizeValue [owner=(a | b) cacheReadPrefetch=(TRUE | FALSE)]
Parameter | Description |
---|---|
drive or drives | The disk drives that you want to assign to the logical drive that you want to create. Specify the enclosure ID and slot ID for each disk drive that you assign to the logical drive. Enclosure ID values are 0 to 99. Slot ID values are 1 to 32. Enclose the enclosure ID values and the slot ID values in parentheses. |
array | The name of the array in which you want to create the new logical drive. (To determine the names of the arrays in your storage subsystem, run the show storageSubsystem profile command.) |
newArray | This parameter enables the user to specify a name for a new array that is automatically created by the controller. |
userLabel | The name that you want to give the new logical drive. Enclose the new logical drive name in double quotation marks (“ ”). |
capacity | The size of the logical drive that you are adding to the storage subsystem. Size is defined in units of bytes, KB, MB, GB, or TB. |
offset | The number of blocks from the start of the array to the start of the referenced logical drive. |
raidLevel | The RAID level of the array that contains the disk drives. Valid values are 0, 1, 3, 5, or 6. |
segmentSize | The amount of data (in KB) that the controller writes on a single disk drive in a logical drive before writing data on the next disk drive. Valid values are 8, 16, 32, 64, 128, 256, or 512. |
owner | The controller that owns the logical drive. Valid controller identifiers are a or b, where a is the controller in slot A, and b is the controller in slot B. If you do not specify an owner, the controller firmware determines the owner. |
cacheReadPrefetch | The setting to turn on or turn off cache read prefetch. To turn off cache read prefetch, set this parameter to FALSE. To turn on cache read prefetch, set this parameter to TRUE. |
You can use any combination of alphanumeric characters, hyphens, and underscores for the names. Names can have a maximum of 30 characters.
The owner parameter defines which controller owns the logical drive. The preferred controller ownership of a logical drive is the controller that currently owns the array.
The size of a segment determines how many data blocks that the controller writes on a single disk drive in a logical drive before writing data on the next disk drive. Each data block stores 512 bytes of data. A data block is the smallest unit of storage. The size of a segment determines how many data blocks that it contains. For example, an 8-KB segment holds 16 data blocks. A 64-KB segment holds 128 data blocks.
When you enter a value for the segment size, the value is checked against the supported values that are provided by the controller at run time. If the value that you entered is not valid, the controller returns a list of valid values. Using a single disk drive for a single request leaves other disk drives available to simultaneously service other requests.
If the logical drive is in an environment where a single user is transferring large units of data (such as multimedia), performance is maximized when a single data transfer request is serviced with a single data stripe. (A data stripe is the segment size that is multiplied by the number of disk drives in the array that are used for data transfers.) In this case, multiple disk drives are used for the same request, but each disk drive is accessed only once.
For optimal performance in a multiuser database or file system storage environment, set your segment size to minimize the number of disk drives that are required to satisfy a data transfer request.
Cache read prefetch lets the controller copy additional data blocks into cache while the controller reads and copies data blocks that are requested by the host from disk into cache. This action increases the chance that a future request for data can be fulfilled from cache. Cache read prefetch is important for multimedia applications that use sequential data transfers. The configuration settings for the storage subsystem that you use determine the number of additional data blocks that the controller reads into cache. Valid values for the cacheReadPrefetch parameter are TRUE or FALSE.
5.43
7.10 adds RAID 6 Level capability and the newArray parameter.