Starting with the 6.2 release, we added a feature to help with this problem, at least for CIFS clients. If you turn on the cifs.snapshot_file_folding.enable option, the filer will compare newly written files with the same file in the last snapshot, and any identical blocks will not result in new allocation of space. The effect of this is to only allocate storage for blocks that have changed. This is also useful when you are doing SnapMirror, since only the changed blocks have to be transmitted.

Naturally, there is some performance impact to this, but it seems to be a good tradeoff for many customer environments.

Mark Muhlestein -- Network Appliance Engineering

-----Original Message----- From: stefan.holzwarth@zentrale.adac.de [mailto:stefan.holzwarth@zentrale.adac.de] Sent: Tuesday, August 06, 2002 1:08 AM To: toasters@mathworks.com Subject: Snapshot storage

Hi,

since about 1 year we have a F760 with now 3 TB of Raw Storage. During that time a snap reserve of 10% was sufficent. (4 a day, 7 per week, 4 per month) But now i found that on one volume the snapshot demand was suddenly growing.

After looking around i found some users using their quota for doing backups to our filer. That backups were deleted after 2 weeks and replaced by new backups. This led to a large amount of data invisible to the quota system, but wasting a lot of snapstorage.

How can i deal with that situation and especialy: how to find users/qtrees with a lot of changed data?

Regards Stefan holzwarth

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-- Stefan Holzwarth ADAC e.V. (Informationsverarbeitung - Systemtechnik - Basisdienste) Am Westpark 8, 81373 München, Tel.: (089) 7676-5212, Fax: (089) 76768924 mailto:stefan.holzwarth@zentrale.adac.de