Dell 36XX, 34XX, 38XX Re-Create Remote Replication Repository Virtual Disk, Cache Read Prefetch

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.

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.

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.

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.

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

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.

Syntax

User-Defined Physical Disks

recreate storageArray replicationRepository repositoryRAIDLevel=(1 5 6)

repositoryPhysicalDisks=(enclosureID1,drawerID1,slotID1 ...

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