Administrator Guide

Table Of Contents
About Compression Statistics
Compression statistics assess the overall space-savings achieved within a storage pool, a member, or a volume, including replicated
volumes. These statistics are accessible through the GUI or the CLI. After starting compression initially or resuming it from a
suspended state, it might be several hours before any new compression activity occurs.
NOTE: When a compressed snapshot is cloned or rolled back, the compression statistics will indicate that the space has
been rehydrated. Base volumes with compressed pages are not supported.
Compression Statistics by Pool
Pool-level compression statistics allow you to assess the overall space-savings achieved by all compression-capable members in a
storage pool. The following status information is provided:
Expanded size – The space required if all the compressed snapshots stored on all members of the storage pool were rehydrated.
Compressed size – The space currently being used by all compressed snapshots on all members of the pool.
Space savings – The amount of space being saved in the storage pool; the dierence between the expanded size and the
compressed size.
Compression Statistics by Member
Member-level compression statistics allow you to assess the overall space-savings achieved within a member as a result of using the
compression feature. The following status information is provided:
Expanded size – The space required if all compressed snapshots stored on that member were rehydrated.
Compressed size – The space currently being used by all compressed snapshots on that member.
Space savings – The amount of space being saved on the member; the dierence between the expanded size and the
compressed size.
Compression Statistics by Volume
Volume-level compression statistics allow you to assess the overall space-savings achieved within a volume as a result of using the
compression feature. The following status information is provided:
Expanded size – The space required if all compressed snapshots in that volume were rehydrated.
Compressed size – The space currently being used by all compressed snapshots in that volume.
Space savings – The amount of space being saved on the volume; the dierence between the expanded size and the
compressed size.
Member Compression States
Table 32. Member Compression States describes the possible member compression states.
Table 32. Member Compression States
Member State Description
No-Capable-Hardware Compression cannot be enabled on this member due to its hardware capabilities.
Not Started Compression has never been successfully enabled on this member.
Running Compression is currently running on this member.
Suspended Compression has previously been enabled and is now paused.
Unknown The compression state of the member cannot be determined due to the member being
oine or an internal error condition.
138
PS Series Group Operations