ONTAP Discussions

What is the difference between SnapVault and deduplication?

lfreeman
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SnapVault is not the same as NetApp deduplication, but they are close cousins - and cousins that work well together. SnapVault works by backing up only the data that has changed since the last backup session. Think of it as an "incrementals forever" approach to backups. This approach minimizes the data transferred and stored per backup. NetApp adds a little magic to make each SnapVault backup session "look" as though it were a full backup, turnng complicated data restores into a very easy procedure.

NetApp deduplication, on the other hand, hides in the background - waiting to spot duplicate data blocks after they are written to the backup destination by SnapVault. Even though SnapVault does a good job of preventing duplicate data from being stored, some duplicate data can still slip through - where NetApp dedupe is ready to scoop up and remove those duplicates. Best of all, NetApp dedupe is "SnapVault aware" and runs automatically with no need for user intervention.

Using SnapVault and dedupe together results in very high space savings ratios. 30 day retention of full backups usually requires only about 1.2X the capacity of the original backup; a space savings of 20:1 or more.

Dr Dedupe

5 REPLIES 5

friea
3,448 Views

Are there certain applications or environments where people are more likely to use both SnapVault and dedupe?

alapaquette
3,448 Views

hi,

For me the snapvault or the snapmirroir are verry good for marriage whith deduplication mode, in all environnement , i don't know about sgbd data.

alap the little frenchy.

ronhohoho
3,448 Views

Snapvault works on most environment except SQL dump volume. If the DBA uses the FlexVol as a "parking lot" for SQL dump, do NOT use SnapVault. The target volume could blow up in 2 weeks unless the SQL dump retention is less than 1 week; the delta is too much even dedup is enabled. However, if there is a SM for SQL in place, there should not be any issue.

Ron

mikesicarup
3,448 Views

I've been reading up on dedup, and decided to apply deduplication to an existing SnapVault destination volume (via the OnCommand gui).  After a day, it reported an impressive 17%.  However, I could swear there was not additional space available.  Checking out the capacity graph from Operations Manager showed an increase increase in deduplication savings, but no corresponding decrease in used capacity.

The SnapVault source volume was already deduped.  There is a rather large snapshot on the night after the deduplication was ran.  Is the dedup information pushed to this snapshot?  I need to wait until this snapshot rolls off before I reclaim available space?  I just want to make sure I understand it correctly, and I'm implementing correctly.

ronhohoho
3,448 Views

The capacity graph shows the "effective" use which means how much data actuall before dedup. you can configure the OpsMan in "File System" and view the report "Volume Space Saving - Deduplication and LUN/File Clones" to see the saving. If you don't have this report, you might need to create one yourself. For reference, read "Storage monitoring and reporting" section on

 

Operations Manager Administration Guide

Ron

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