DELL 34XX User Manual
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 disk
group that are used for data transfers.) In this case, multiple physical disks are used for the same request,
but each physical disk is accessed only once.
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 disk
group that are used for data transfers.) In this case, multiple physical disks are used for the same request,
but each physical disk 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 physical disks that are required to satisfy a data transfer request.
size to minimize the number of physical disks that are required to satisfy a data transfer request.
Cache Read Prefetch
Cache read prefetch lets the RAID controller module copy additional data blocks into cache while the
RAID controller module 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 array that you use determine the number of additional data blocks that the RAID
controller module reads into cache. Valid values for the cacheReadPrefetch parameter are TRUE or
FALSE.
RAID controller module 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 array that you use determine the number of additional data blocks that the RAID
controller module reads into cache. Valid values for the cacheReadPrefetch parameter are TRUE or
FALSE.
Reserved Space on Physical Disks
The controller firmware reserves 5 GB of space on each drive in a disk group or disk pool for future
expansion of the DACstore. The space must be adjacent to the DACstore or it will not be reserved. The
reserved space is defined only when you create the disk group or disk pool. Unassigned physical disks
and hot spare physical disks will not have reserved space. After the disk group or disk pool has been
created, the reserved space is persistent. If a storage array is being upgraded to controller firmware 8.20,
disk groups or disk pools that were created under a previous version of controller firmware will not be
affected; that is, the additional space will not be reserved on existing disk groups or disk pools.
expansion of the DACstore. The space must be adjacent to the DACstore or it will not be reserved. The
reserved space is defined only when you create the disk group or disk pool. Unassigned physical disks
and hot spare physical disks will not have reserved space. After the disk group or disk pool has been
created, the reserved space is persistent. If a storage array is being upgraded to controller firmware 8.20,
disk groups or disk pools that were created under a previous version of controller firmware will not be
affected; that is, the additional space will not be reserved on existing disk groups or disk pools.
Re-Create Remote Replication Repository Virtual Disk
Description
NOTE: This command is valid only with Fibre Channel storage arrays.
This command creates a new Remote Replication repository virtual disk (also called a replication
repository virtual disk) by using the parameters defined for a previous replication repository virtual disk.
The underlying requirement is that you have previously created a replication repository virtual disk. When
using this command, the replication repository virtual disk can be defined in one of three ways:
• User-defined physical disks
• User-defined disk group
• User-defined number of physical disks
repository virtual disk) by using the parameters defined for a previous replication repository virtual disk.
The underlying requirement is that you have previously created a replication repository virtual disk. When
using this command, the replication repository virtual disk can be defined in one of three ways:
• User-defined physical disks
• User-defined disk group
• User-defined number of physical disks
If you choose to define a number of physical disks, the RAID controller module firmware chooses which
physical disks to use for the replication repository virtual disk.
physical disks to use for the replication repository virtual disk.
Syntax
User-Defined Physical Disks
recreate storageArray replicationRepository repositoryRAIDLevel=(1 | 5 | 6)
repositoryPhysicalDisks=(enclosureID1,drawerID1,slotID1 ...
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