Dell PowerVault MD3000 - Manual (Page 59)

Configuring a Storage Array
59
• Initialization
• Changing segment size
• Defragmentation of a disk group
• Adding free capacity to a disk group
• Changing the RAID level of a disk group
The lowest priority rate favors system performance, but the modification
operation takes longer. The highest priority rate favors the modification
operation, but the system performance might be degraded.
The set virtualDisk command enables you to define the modification priority
for a virtual disk. The following syntax is the general form of the command:
set (allVirtualDisks | virtualDisk
[virtualDiskName] | virtualDisks [ virtualDiskName1
... virtualDiskNamen ] | virtualDisk < wwid > |
accessVirtualDisk) modificationPriority=(highest |
high | medium | low | lowest)
The following example shows how to use this command to set the
modification priority for virtual disks named Engineering 1 and
Engineering 2:
client>smcli 123.45.67.89 -c "set virtualDisks
[\"Engineering_1\" \"Engineering_2\"]
modificationPriority=lowest;"
The modification rate is set to lowest so that system performance is not
significantly reduced by modification operations.
Assigning Global Hot Spares
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 and 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 levels 1 or 5.