Real-Time Compression - IBM Storwize V5010 Manual

For example, if a warning of 80% is specified, the warning is logged when 20% of the free
capacity remains. This approach is similar to the capacity warning that is available on storage
pools.
A thin-provisioned volume can be converted to a either a fully allocated volume or
compressed volume by using volume mirroring (and vice versa).
The Thin Provisioning feature is included as part of the base software, and no license is
required.

1.7.3 Real-time Compression

The Storwize V5030 model can create compressed volumes, allowing more data to be stored
in the same physical space. IBM Real-time Compression™ (RtC) can be used for primary
active volumes and with mirroring and replication (FlashCopy/Remote Copy). RtC is available
on the Storwize V5030 model only.
Existing volumes can take advantage of Real-time Compression to result in an immediate
capacity saving. An existing volume can be converted to a compressed volume by creating a
compressed volume copy of the original volume followed by deleting the original volume.
No changes to the existing environment are required to take advantage of RtC. It is
transparent to hosts while the compression occurs within the IBM Storwize V5000 Gen2
system.
Software-only compression: The use of RtC on the Storwize V5030 requires dedicated
CPU resources from the node canisters. If more performance is required for deploying RtC,
consider purchasing the Storwize V7000 system. The Storwize V7000 system uses
dedicated hardware options for compression acceleration.
The Storwize V5030 model has the additional memory upgrade (32 GB for each node
canister). When the first compressed volume is created 4 of the 6 CPU cores are allocated to
RtC. Of the 32 GB of memory on each node canister roughly 9-10 GB is allocated to RtC.
There are no hardware compression accelerators as in the Storwize V7000 Gen2. The actual
LZ4 compression is done by the CPUs as was the case with the Storwize V7000 Gen1.
Table 1-13 shows how the cores are used with RtC.
Table 1-13 Cores usage with RtC
Model
V5010
V5020
V5030
The faster CPU with more cores, the extra memory and the hyper-threading capability of the
Storwize V5030, as well as improvements to RtC software results in good performance for
smaller customer configurations common to the market segment this product is intended to
serve. The feature is licensed per enclosure. Conversely, Real-time Compression is not
available on the Storwize V5010 or Storwize V5020 models.
Compression Disabled
Normal RtC
Processing
2 cores NA
2 cores NA
6 cores 0 cores
Chapter 1. Overview of the IBM Storwize V5000 Gen2 system
Compression Enabled
Normal RtC
Processing
NA NA
NA NA
2 cores 4 cores + HT
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