Netbackup Catalog (6.0) and Microsoft DFS-R

[Dan_Lynch]

Has anyone tried to use DFS-R to replicate the Netbackup Catalog?  We have used it with a lot of success in other systems in our environment, and I was wondering if anyone has any input.  Our NBU master server is fairly busy with around 1500 jobs per day, for what it's worth, and our full / differential hot catalog backups just aren't quite giving us as much comfort as we would like.

Thanks!

[Ron_Cohn]

Dan,

What comfort level are you talking about?  Is it be because you are only outputting to 1 device?  If so, there are other avenues.

[Dan_Lynch]

I mean comfort that at roughly any given time, the "replicated" catalog data could be presented to a warm-standby server at another site beit for disaster recovery or a true disaster.  We would like to avoid using Storage Foundation for mirroring and may think of using some back end storage mirroring like flashcopy, but it seems that DFS-R would be nice and simple if of course it's reliable in this scenario.

Hope that explains where we're trying to go with it...

[Ron_Cohn]

Interesting approach (I like it...).  My only question is:  Do you have the bandwidth to replicate such a large file?  Our catalog is +20GB.  I can only dream about moving that much data in a reasonable amount of time.

[Dan_Lynch]

Our catalog is around 100 GB right now...We have a gigaman line which is 1 Gbit/s - we keep one volume with acronis/ghost/ntbackup images in sync and it's about 750 GB-1 TB per week in changes - DFS-R gives us about a 40-60% reduction in the bandwidth that goes over because it only copies deltas.  I would expect the netbackup catalog to be at least as good once the initial load is complete, but then again the catalog is constantly in flux and I'm not sure if it works one time it wouldn't at another...I am probably most concerned about a performance impact because the catalog currently only sits on 3 spindles and our catalog backup speeds rarely get over 15 MB/s.  And I would test it, but as most probably well know, setting up an identical NBU environment with production level load is difficult at best.

[Ron_Cohn]

I do not know how DFS-R would handle an "Open File" condition, but give it a shot.  Please update this thread as you get results.  Good luck!

[bakitup · Accepted solution]

You will need to perform a hot catalog backup of the Sybase database or else you will have an inconsistent database and not be able to bring up NetBackup.  /usr/openv/db or %installpath%\veritas\db (I think on windows) is the location and has a script to perform a backup of database.

We do a similar thing on a UNIX master, but perform a Sybase backup first (Volume and Device Database), then use rsync to get a copy of everything on an NFS mount. 

A seperate thing but related to DFS-R.  NetBackup 6.0MP6 will NOT backup data in the replicated area with the DFS-R service running yet the backup will complete with a 0 status code.  It would back it up in MP5, but will not in MP6. If you are running 6.0MP6 on a server running DFS-R make sure you can restore the data.   BEWARE>>>>