Dell PowerVault MD3000i Command Line Interface Guide - Page 98

where segmentSizeValue is the new segment size you want to set. Valid segment size values are 8, 16, 32, 64, 128, 256, and 512. You can identify the virtual disk by name or World Wide Identifier (WWID) (see "Set Virtual Disk" on page 189). Defragmenting a Disk Group When you defragment a disk group, you consolidate the free capacity in the disk group into one contiguous area. Defragmentation does not change the way in which the data is stored on the virtual disks. As an example, consider a disk group with five virtual disks. If you delete virtual disks 1 and 3, your disk group is configured in the following manner: space, virtual disk 2, space, virtual disk 4, virtual disk 5, original unused space When you defragment this group, the space (free capacity) is consolidated into one contiguous location after the virtual disks. After being defragmented, the disk group is: virtual disk 2, virtual disk 4, virtual disk 5, consolidated unused space To defragment a disk group, run the following command: start diskGroup [diskGroupNumber] defragment where diskGroupNumber is the identifier for the disk group. NOTE: Defragmenting a disk group starts a long-running operation. Troubleshooting and Diagnostics If a storage array exhibits abnormal operation or failures, you can use the commands described in this section to determine the cause of the problems. Collecting Physical Disk Data To gather information about all the physical disks in a storage array, run the save allPhysicalDisks command. This command collects sense data from all the physical disks in a storage array and saves the data to a file. The sense data consists of statistical information maintained by each of the physical disks in the storage array. 98 Maintaining a Storage Array