Accusys ExaRAID GUI - Manual (Page 217)

Advanced Functions
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• Defragment a disk group to consolidate free chunks
All existing free chunks are deleted, and a single free chunk at the end of
the disk group is created.
5.5.2 Logical disk shrink
Logical disk shrink can be used to decrease the capacity of a logical disk.
When performing logical disk shrink, the capacity of the corresponding
LUNs will be modified immediately and any attempt to access to the
space beyond the new capacity will be rejected. You have to shrink the
partition and the file system on the host computer before shrinking the
logical disks in order to avoid data loss.
• Shrink logical disk with an adjacent free chunk
When a logical disk is shrunk, the free chunk right after the logical disk is
expanded by the capacity reduced at the shrunk logical disk.
DG DG
LD 0
LD 1
LD 2
LD 0
LD 1
LD 2
free chunk 2
free chunk 0
disk group
defragment
free chunk 1
free chunk 0
Figure 5-17 Defragment a disk group to expand the last
free chunk
DG DG
disk group
defragment
LD 0
LD 1
LD 2
LD 0
LD 1
LD 2
free chunk 1
free chunk 0
free chunk 0
Figure 5-18 Defragment a disk group to consolidate free
chunks