When using Unisphere to create new storage groups, PowerMax compression is enabled by default. You can disable PowerMax compression by unchecking the compression checkbox in the SG creation wizard. Unisphere also includes views and metrics that show the compression ratio of compressed storage groups, potential compressibility of uncompressed storage groups, and more. The following section shows how to perform these operations or display data reduction-related information by using the Solutions Enabler Command Line Interface (CLI).
A storage group (data_sg in the examples) must be associated with the PowerMax storage system’s Storage Resource Pool (SRP) to enable compression. To enable compression and associate the SRP, type the following command:
# symsg -sg data_sg set -srp SRP_1 -compression
Similarly, to disable compression on a storage group where compression is enabled, type the following command:
# symsg -sg data_sg set -srp SRP_1 -nocompression
To display the compression ratio of a storage group, type the following command.
# symcfg list -tdev -sg data_sg –gb [-detail]
To display the estimated compression ratio of storage groups, including SGs with compression disabled, type the following command:
# symcfg list -sg_compression -by_compressibility -all
To display overall system efficiency, type the following command:
# symcfg list -efficiency -detail
For more information about the PowerMax Adaptive Compression Engine and deduplication, see Data Reduction with Dell EMC PowerMax.