You can resume an efficiency operation by using the sis start command with the checkpoint option.
If only deduplication is enabled on the volume, deduplication runs on the data. However, if deduplication and data compression are enabled, data compression runs on the existing data followed by deduplication.
You can view the details of the checkpoint for a volume by using the sis status command.
By default the efficiency operations resume from checkpoints. However, if a checkpoint corresponding to a previous efficiency operation (the phase when the sis start -s command is run) is older than 24 hours, then the efficiency operation does not resume from the previous checkpoint automatically. In this case, the efficiency operation starts from the beginning. However, if you know that significant changes have not occurred in the volume since the last scan, you can force continuation from the previous checkpoint by using the -p option.
The following command enables you to resume an efficiency operation by using the checkpoint option on the volume VolA: sis start -sp /vol/VolA
