Re: [Veritas-bu] NetBackup long retention does dedup help

On Mon, May 4, 2009 at 11:41 AM, Harmon, Patricia K. <PHarmon AT tecoenergy DOT com> wrote:

We backup about 45t a week that has a retention of 8 years. We backup to disk and dup to LTO3 tapes with few issues. Except the tape budget is killing us.

Anybody out there have long retentions? Does de-dupe help save tapes? We have few restores, so keeping data on disk is not a priority with us.

As always, it depends. If you're backing up the same 45TB every week, then de-dupe will be very beneficial to you. If you're backing up 45TB of unique data every week, and the data blocks don't match what you backed up any other week, then you won't de-dupe at all. For example, if those 45TB happen to be tiff images of customer statements, then forget about it. If they're C: drive backups of 10,000 Windows servers, then you'll probably de-dupe very, very well.

You need to do a thorough analysis of what the data is you're backing up. The first objective, of course, is to back up less. If you can identify 800GB, and that's only 1.7%, of your data that doesn't need to be backed up, and assuming that you're getting 2:1 compression so you use 1 less tape per week, then you've saved about 52*8 tapes at roughly $25 per tape, or $10K over 8 years.

Don't forget that de-duping isn't an all-or-nothing solution. You may de-dupe in some places where it makes sense but not others.

.../Ed

Ed Wilts, RHCE, BCFP, BCSD, SCSP, SCSE
ewilts AT ewilts DOT org

_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu