NetApp made the NearStore option, which was a prerequisite for deduplication, free. Since NearStore is a prerequisite, you’ll need to be sure to license that first:
license add <Code for NearStore>
license add <Code for Deduplication>
Once deduplication is licensed, then you can enable it on a per-volume basis using the “sis on” command:
sis on /vol/<volname>
Note, however, that the volume cannot exceed a certain size, based on the storage system model, in order for deduplication to work. These volume size limits are laid out in TR3505. Note that the volume must never have been any bigger than the size limits described, so this means you can’t size it down to the limits set forth and then run deduplication.
Once it’s running, you can check the status with:
sis status /vol/<volname>
After it’s finished running, you can see your space savings like this:
df -s /vol/<volname>
After running deduplication on a small NFS volume that housed only three VMs, the “df -s” command showed a space savings of 64%. That’s pretty impressive!
Moving forward, deduplication will run automatically every night at midnight, as shown by this command:
sis config /vol/<volname>
That should be enough to get most everyone started. Feel free to post comments or corrections below.