A deduplicated volume or volume copy can be created in
a data reduction pool. When you implement deduplication, you must
consider specific requirements in the storage environment.
Deduplication is a type of
compression that eliminates duplicate copies of data. Deduplication
of user data occurs within a storage pool and only between volumes
or volume copies that are marked as deduplicated. However, there is
no requirement for all nodes in a system, and therefore all I/O groups,
to support deduplication. You can create deduplicated volumes in an
I/O group when no compressed volumes or volume copies are in regular
storage pools (that is, when real-time
compression is in use on that I/O group).
You can migrate any type of volume from a regular storage pool
to a data reduction pool. You can also migrate any existing real-time
compressed volume to a data reduction pool. After you migrate a volume
to a data reduction pool, you can then create a deduplicated volume.
The following software and hardware requirements are needed for
deduplication. There are also update and performance considerations.
- Code level 8.1.2 or higher is needed for
data reduction pools.
- Code level 8.1.3 or higher is needed for
deduplication.
- Nodes must have at least 32 GB memory to support deduplication.
- Nodes that have more than 64 GB memory can use a bigger deduplication
fingerprint database, which might lead to better deduplication.
- You
can use the Data Reduction Estimator Tool (DRET) to estimate how much
capacity you might save if a standard volume that a host can access
was a deduplicated volume. The tool scans target workloads on all attached storage arrays, consolidates these
results, and generates an estimate of potential data reduction savings for the entire system.
Go to https://www-945.ibm.com/support/fixcentral/ to find the tool and its readme. Data reduction is only supported Lenovo Storage V5030 and Lenovo Storage V5030F systems.
Note: Data Reduction Estimator Tool also
provides some analysis of potential compression savings for volumes;
however, it is recommended that you also use management GUI or the
command-line interface to run the integrated Comprestimator Utility
to gather data for potential compression savings for volumes in data
reduction pools.
Real-time compression and deduplication are not supported in the
same I/O group. However, data reduction compression and deduplication
might be supported on certain platforms.
Table 1 details
the features that are supported on each platform.
Table 1. Supported compression features. The table describes the types of compression
features that are supported on each model.
| Product |
Platform |
Node/canister memory (GBs) |
Supported features |
| Real-time compression |
DRP |
Compression |
Deduplication |
| 9846-AF8 and 9848-AF8 |
| Lenovo Storage V series |
V5030 (32 GB) |
32 |
Yes1 |
Yes |
Yes1 |
Yes |
| V5030 (16 GB) |
16 |
No |
Yes |
No |
No |
| V3700 XP |
8/16 |
No |
Yes |
No |
No |
| V3700 |
8 |
No |
Yes |
No |
No |
- 1 - Does not support data reduction compression
and real-time compression in the same I/O group at the same time.