IBM XIV Gen3 Series, Planning Manual

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Estimating compression savings using XIV GUI
The XIV software provides a built-in comprestimator function from the XIV
Management Tools GUI on an XIV system supporting Real-time Compression.
From the XIV GUI, compressible data can be identified and expected compression
ratios can be estimated even before using compression. Compression does not even
have to be enabled to view compression saving estimates. Continuous saving
estimates are visible at all times for uncompressed volumes. And the compression
ratio for all uncompressed volumes in the system is continuously estimated in a
cyclical manner. That is, the potential savings estimations appear continuously and
are updated every few hours.
The decision to use compression can be based on the expected storage savings of
the compressed data and the expected effect on performance (throughput and
latency) of the compression processing overhead.
Figure 1 displays the compression savings (in both percentage and GB values) of
compressed volumes and uncompressed volumes with estimates of potential
savings, should the uncompressed volumes be compressed. These potential
compression savings are constantly being updated.
Compression Saving and Compression Saving (%) appear on the following views:
v Storage Pools
v
Volumes by Pools
v Volumes and Snapshots
v Consistency Groups
v Domains
v Systems list
Estimating compression savings using IBM Comprestimator
utility
Comprestimator is a stand-alone tool that can be used to estimate compression
savings for data that is either not on XIV storage, or on an XIV Gen2 or Gen3
storage system with system software earlier than 11.6.x.
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Figure 1. Compression savings in the Volumes by Pools view
Chapter 3. Planning for compression
9