Dell PowerVault MD3000 - Manual (Page 155)

Script Commands
155
Additional Information
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 RAID controller module owns the volume.
The preferred controller ownership of a volume is the RAID controller
module that currently owns the disk group.
Segment Size
The size of a segment determines how many data blocks that 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 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 RAID controller module at run
time. If the value that you entered is not valid, the RAID controller module
returns a list of valid values. 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 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 physical disks in the volume
owner RAID controller module that owns the virtual disk.
Valid RAID controller module identifiers are 0 or 1,
where 0 is the RAID controller module in Slot 0 and 1
is the RAID controller module in Slot 1. If you do not
specify an owner, the RAID controller module
firmware determines the owner. For information about
the owner parameter, see "Creating Virtual Disks with
User-Assigned Physical Disks" on page 48
.
cacheReadPrefetch The setting to turn on or turn off cacheReadPrefetch.
To turn off cacheReadPrefetch, set this parameter to
FALSE. To turn on cacheReadPrefetch set this
parameter to TRUE.
Parameter Description