3PAR InForm® OS 2.3.1 CLI Administrator's Manual (320-200180 Rev B, February 2010)

16.10
Compacting Logical Disks
3PAR InForm CLI Administrator’s Manual InForm OS Version 2.3.1
16.8 Compacting Logical Disks
Reclaim unused Logical Disk (LD) space with the compactcpg command. When multiple
identical virtual volumes are created as a result of a single volume creation operation, the
underlying logical disks that support those volumes are shared by the volume group. If several
of the members of that volume group are later deleted, the underlying logical disks may
become less efficient in the usage of space. One or more logical disks shared by the volume
group may have only a small portion of their regions mapped to existing virtual volumes.
However, their unused regions are not available to the system for use in creating new logical
disks. Compacting the logical disk regions mapped to these volumes may recover and free
logical disk space. For more information about how the InServ Storage Server manages space
usage, see the 3PAR InForm OS Concepts Guide.
You can compact logical disks for a group of volumes that share logical disks with the
compactld command. Existing regions on the fragmented logical disks are migrated to new,
fully use logical disks and the older ones are deleted so that unused space can be returned to
the system’s free chunklet pool.
 To reclaim unused logical disk space from the group of virtual volumes, issue the
compactld <LD_name> or compactld -pat <pattern> command, where:
◆ <LD_name> is the name of the LD you wish to compact.
◆ <pattern> displays all LDs that match the pattern.
Refer to the InForm OS Command Line Interface Reference and CLI Help for detailed
information about this command.
16.9 Compacting Common Provisioning Groups
Reclaim unused Common Provisioning Group (CPG) space with the compactld command.
CPGs provide a shared pool of logical disk capacity for use by all virtual volumes that draw
space from that pool. If volumes that draw from a CPG are deleted, or if copy space for these
volumes grows and then shrinks, the underlying logical disks in the CPG pool can become less
efficient in space usage. Compacting a CPG allows you to reclaim space from a CPG that has
become less efficient in space usage from creating, deleting, and relocating volumes.
Compacting consolidates logical disk space in CPGs into as few logical disks as possible. For
more information about how the InServ Storage Server manages space usage, see the 3PAR
InForm OS Concepts Guide.