3PAR InForm® OS 2.3.1 Concepts Guide (320-200112 Rev B, February 2010)

11.3
Reclaiming Unmapped Logical Disk Space from Volumes
InForm OS Version 2.3.1 3PAR InForm OS Concepts Guide
pool may have only a small portion of their regions mapped to existing virtual volumes.
However, the logical disk’s unused regions are not available for use by the volumes mapped to
the CPG. Compacting the logical disk regions mapped to these volumes may recover and free
logical disk space.
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. Compacting CPGs can be performed
with both the 3PAR InForm Command Line Interface (CLI) and the 3PAR InForm Management
Console. Refer to the 3PAR InForm OS CLI Administrator’s Manual and the 3PAR InForm
Management Console Online Help for instructions on how to perform this task.
11.3 Reclaiming Unmapped Logical Disk Space from Volumes
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.
Compacting logical disks can only be performed with the 3PAR InForm Command Line
Interface (CLI). Refer to the 3PAR InForm OS CLI Administrator’s Manual for instructions on
how to perform this tasks.
You can use the optional Dynamic Optimization feature to configure volumes to use space
more efficiently. To learn about tuning volumes for optimal performance, see Chapter 12,
Enhanced Storage Applications.
11.4 Automatically Reclaiming Unused Snapshot Space from Volumes
The InForm OS automatically reclaims unused snapshot and administration space from Thinly-
Provisioned Virtual Volumes (TPVVs) and fully-provisioned virtual volumes and returns the
space to the LDs. The system examines the snapshot and administration space for large areas of
unused space. The identified areas are unmapped from the corresponding LD regions and the
space is returned to the LDs.