Autoconfigure Storage Array

Autoconfigure Storage Array

This command automatically configures a storage array. Before entering the autoConfigure storageArray command, enter the show storageArray autoConfiguration command. The show storageArray autoConfigure command returns configuration information in the form of a list of valid physical disk types, RAID levels, virtual disk information, and hotspare information. (This list corresponds to the parameters for the autoConfigure storageArray command.) The RAID controller modules audit the storage array and then determine the highest RAID level the storage array can support and the most efficient virtual disk definition for the RAID level. If the configuration described by the returned list is acceptable, you can enter the autoConfigure storageArray command without any parameters. If you want to modify the configuration, you can change the parameters to meet your configuration requirements. You can change a single parameter or all parameters. After you enter the autoConfigure storageArray command, the RAID controller modules set up the storage array using either the default parameters or those you selected.

Syntax

autoConfigure storageArray [driveType=(fibre | SATA | SAS | PATA) raidLevel=(0 | 1 | 3 | 5 | 6) diskGroupWidth=numberOfPhysical Disks diskGroupCount=numberOfVolumeGroups virtual disksPerGroupCount=numberOfVirtual DiskPerGroup hotSpareCount=numberOfHotspares segmentSize=segmentSizeValue cacheReadPrefetch=(TRUE | FALSE)]

Parameters

Parameter Description

driveType
The type of physical disks that you want to use for the storage array. Valid physical disk types are: fibre, SATA, SAS, or PATA. The driveType parameter is not required if only one type of physical disk is in the storage array.

raidLevel
The RAID level of the disk group that contains the physical disks in the storage array. Valid RAID levels are 0, 1, 3, 5, or 6.

diskGroupWidth
The number of physical disks in a disk group in the storage array.

diskGroupCount
The number of disk groups in the storage array. Use integer values.

virtual disksPerGroupCount
The number of equal capacity virtual disks per disk group. Use integer values.

hotSpareCount
The number of hot spares you want in the storage array. Use integer values.

segmentSize
The amount of data (in kilobytes) the RAID controller module writes on a single physical disk in a virtual disk before writing data on the next physical disk. Valid values are 8, 16, 32, 64, 128, 256, or 512.

cacheReadPrefetch
This parameter turns on or turns 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.

Notes

A disk group is a set of physical disks logically grouped together by the RAID controller modules in the storage array. The number of physical disks in a disk group depends on the size of physical disks available for the disk group. The following list relates physical disk capacity to the number of physical disks in a disk group:

18 and 36 GB physical disks, 30 physical disks maximum in the disk group
73 GB physical disks, 28 physical disks maximum in the disk group
180 GB physical disks, 11 physical disks maximum in the disk group

A 73 or 180 GB physical disk will not report exactly 73 or 180 GB as its capacity. The limitation for the number of large physical disks in a disk group is the two terrabyte size restriction.

Hot spare physical disks can replace any failed physical disk in the storage array. The hot spare must be the same type of physical disk as the physical disk that failed (that is, a SATA hot spare cannot replace a Fibre Channel physical disk). A hot spare must have capacity greater than or equal to any physical disk that can fail. If a hot spare is smaller than a failed physical disk, the hot spare cannot be used to rebuild the data from the failed physical disk. Hot spares are available only for RAID level 1, 3, 5, or 6. The maximum number of SCSI hot spares is equal to the number of SCSI physical disk channels supported by the RAID controller module. The maximum number of Fibre Channel hot spares per storage array is 15.

The size of a segment determines how many data blocks the RAID controller module writes on a single physical disk in a virtual disk before writing data on the next physical disk. 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 blocks 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 provided by the RAID controller module at run time. If the value you enter is not valid, the RAID controller module returns a list of valid values. For optimal performance in a multi-user database or file system storage environment, set your segment size to minimize the number of physical disks needed to satisfy a data transfer request. Using a single physical disk for a single request leaves other physical disks available to simultaneously service other requests. If the virtual disk is in a single-user large data transfer environment (such as multi-media) performance is maximized when a single data transfer request is serviced with a single data stripe. (A data stripe is the segment size multiplied by the number of physical disks in the disk group that are used for data transfers.) In this case, multiple disks are used for the same request, but each disk is only accessed once.

If you set the cache block size to 16, then you cannot create a virtual disk with a segment size of 8.

Cache read prefetch enables the RAID controller module to copy additional data blocks into cache while the RAID controller module reads and copies data blocks 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 number of additional data blocks that the RAID controller module reads into cache is determined by the storage array configuration settings that you use. Valid values for the cacheReadPrefetch parameter are 0 or 1. If you enter any value greater than 1, the RAID controller module treats that value as if it were a 1 and turns on cache read prefetch.

Minimum Firmware Level

6.10
7.10 adds RAID 6 and SAS

Parameter	Description
`driveType`	The type of physical disks that you want to use for the storage array. Valid physical disk types are: fibre, SATA, SAS, or PATA. The `driveType` parameter is not required if only one type of physical disk is in the storage array.
`raidLevel`	The RAID level of the disk group that contains the physical disks in the storage array. Valid RAID levels are 0, 1, 3, 5, or 6.
`diskGroupWidth`	The number of physical disks in a disk group in the storage array.
`diskGroupCount`	The number of disk groups in the storage array. Use integer values.
`virtual disksPerGroupCount`	The number of equal capacity virtual disks per disk group. Use integer values.
`hotSpareCount`	The number of hot spares you want in the storage array. Use integer values.
`segmentSize`	The amount of data (in kilobytes) the RAID controller module writes on a single physical disk in a virtual disk before writing data on the next physical disk. Valid values are 8, 16, 32, 64, 128, 256, or 512.
`cacheReadPrefetch`	This parameter turns on or turns 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.