System information

Advanced Functions
5-30
• Expand a logical disk by allocating an adjacent free chunk and moving logical disks
If the free chunk right after the selected logical disk is not sufficient for expansion, the controller will allocate the free
chunk and also start a background task to move logical disks.
5.5.4 Disk group expansion
Disk group expansion can be used to increase the useable space of a disk group by adding one or more disks to the disk
group. When the expansion task is complete, the new space is created in the end space of the disk group. Logical disks
can be created in the space set up by the expansion.
• Disk group expansion to expand the last existing free chunk
If the disk group has free chunks in the end space, the capacity of the free chunk will be increased after the expansion.
The capacity of existing logical disks will not be affected.
• Disk group expansion to create a free chunk
If the disk group has no free chunks in the end space before expansion, a new free chunk will be created.
free chunk 1
DG
DG
LD 1
LD 0
LD 1
LD 0
free chunk 0
free chunk 1
LD 2
expand
LD 1
Figure 5-23 Logical disk capacity expansion by allocating an adjacent free chunk
and moving logical disks
Figure 5-24 Disk group expansion by adding new member disks and enlarging the
last free chunk
Disk group (before) Disk group (after)
MD 0 MD 1 MD 2
LD 0
LD 1
LD 2
Free
chunk
MD 0 MD 1 MD 2 MD 3 MD 4
LD 0
LD 1
LD 2
Free
chunk
Disk group (before) Disk group (after)
LD 0
LD 1
LD 2
LD 3
Free
chunk
LD 0
LD 1
LD 2
LD 3
MD 0 MD 1 MD 2 MD 3 MD 4
MD 0 MD 1 MD 2
Figure 5-25 Disk group expansion by adding new member disks and creating a new
free chunk