HP 3PAR InForm OS 3.1.1 CLI Administrator's Manual

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
system manages space usage, see the HP 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 thecompactld
<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 HP 3PAR InForm OS Command Line Interface Reference and CLI Help for detailed
information about this command.
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
system manages space usage, see the HP 3PAR InForm OS Concepts Guide.
• compactcpg <CPG_name> or compactcpg <pattern>
◦ <CPG_name> is the name of the CPG you wish to compact.
◦ <pattern> displays all CPGs that match the pattern.
Refer to the HP 3PAR InForm OS Command Line Interface Reference and CLI Help for detailed
information about this command.
150 Performance Tuning