Specifications

NetApp Deduplication for FAS and V-Series Deployment and Implementation Guide
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and are locking a lot of data. This tends to happen especially when deduplication is run on existing flexible
volumes of data.
Use the snap list command to see what Snapshot copies exist and the snap delete command to
remove them. Alternatively, wait for the Snapshot copies to expire and the space savings to appear (see
section 4.1, ―Deduplication and Snapshot Copies‖).
11.5 UNDEDUPLICATING A FLEXIBLE VOLUME
It is possible, and relatively easy, to undeduplicate a flexible volume that has deduplication enabled by
backing out deduplication and turning it back into a regular (nondeduplicated) flexible volume. This can be
done while the flexible volume is online, as described below.
Turn deduplication off on the flexible volume.
Note: This command stops fingerprints from being written to the change log as new data is written to the
flexible volume. If this command is used, and then deduplication is turned back on for this flexible volume,
the flexible volume must be rescanned with the sis start –s command.
sis off <flexvol>
Use the following command
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to recreate the duplicate blocks in the flexible volume:
sis undo <flexvol>
When this command completes, it deletes the fingerprint file and the change log files.
Here is an example of undeduplicating a flexible volume:
r200-rtp01> df –s /vol/VolReallyBig2
/vol/VolReallyBig2/ 20568276 3768732 15%
r200-rtp01> sis status /vol/VolReallyBig2
Path State Status Progress
/vol/VolReallyBig2 Enabled Idle Idle for 11:11:13
r200-rtp01> sis off /vol/VolReallyBig2
SIS for "/vol/VolReallyBig2" is disabled.
r200-rtp01> sis status /vol/VolReallyBig2
Path State Status Progress
/vol/VolReallyBig2 Disabled Idle Idle for 11:11:34
r200-rtp01> sis undo /vol/VolReallyBig2
Wed Feb 7 11:13:15 EST [wafl.scan.start:info]: Starting SIS volume scan
on volume VolReallyBig2.
r200-rtp01> sis status /vol/VolReallyBig2
Path State Status Progress
/vol/VolReallyBig2 Disabled Undoing 424 MB Processed
r200-rtp01> sis status /vol/VolReallyBig2
No status entry found.
r200-rtp01> df -s /vol/VolReallyBig2
Filesystem used saved %saved
/vol/VolReallyBig2/ 24149560 0 0%
Note: If sis undo starts processing and then there is not enough space to undeduplicate, it stops, sends a
message about insufficient space, and leaves the flexible volume deduplicated. Use df –s to understand how
much free space you really have, and then delete either data or Snapshot copies to provide the needed free
space.
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The undo option of the sis command is available only in the diag mode, accessed using the priv set
diag command.