Run efficiency operations manually on existing data


You can run the efficiency operations manually on the data that exists in volumes prior to enabling deduplication, data compression, or data compaction. You can run these operations by using the volume efficiency start -scan-old-data command.

About this task

If you enable only deduplication on a volume, then deduplication runs on the data. If you enable deduplication, data compression, and data compaction on a volume, then data compression runs first, followed by deduplication and data compaction.

When you run data compression on existing data, by default the data compression operation skips the data blocks that are shared by deduplication and the data blocks that are locked by Snapshot copies. If you choose to run data compression on shared blocks, then optimization is turned off and the fingerprint information is captured and used for sharing again. You can change the default behavior of data compression when compressing existing data.

You can run a maximum of eight deduplication, data compression, or data compaction operations concurrently per node. The remaining operations are queued.


Postprocess compression does not run on AFF platforms. An EMS message is generated to inform you that this operation was skipped.

  1. Use the volume efficiency start -scan-old-data command to run deduplication, data compression, or data compaction manually on the existing data.

    The following command enables you to run these operations manually on the existing data in volume VolA:

    volume efficiency start -vserver vs1 -volume VolA -scan-old-data true [-compression | -dedupe | -compaction ] true