Planning: MD3600i Series Storage Array Terms and Concepts 47

Disk Group Defragmentation

Defragmenting consolidates 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.

Disk Group Operations Limit

The maximum number of active, concurrent disk group processes per
installed RAID contr oller mod ule is on e. This li mit is app lied to th e followi ng
disk group processes:
• Virtual disk RAID level migration
• Segment size migration
• Virtual disk capacity expansion
• Disk group expansion
• Disk group defragmentation.
If a redundant RAID controller module fails with an existing disk group
process, the process on the failed controller is transferred to the peer
controller. A transferred process is placed in a suspended state if there is an
active disk group process on the peer controller. The suspended processes are
resumed when the active process on the peer controller completes or is
stopped.
NOTE: If you try to start a disk group process on a controller that does not have an
existing active process, the start attempt fails if the first virtual disk in the disk group
is owned by the other controller and there is an active process on the other
controller.
RAID Background Operations Priority
The storage array supports a common configurable priority for the following
RAID operations:
• Background initialization
•Rebuild
•Copy back
• Virtual disk capacity expansion
• Raid level migration
book.book Page 47 Thursday, December 9, 2010 3:20 PM