Dell PowerVault MD 32XX/36XX Series Storage Arrays CLI Guide

Modification priority defines how much processing time is allocated for virtual disk modification operations. Time allocated for virtual disk modification operations affects system performance. Increases in virtual disk modification priority can reduce read/write performance. Operations affected by modification priority include:

• Copyback
• Reconstruction
• 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.