SMSQL Backup of very large database files

[dgreg]

Hi,

I'm working on a SQL server storage solution for a customer where the future storage requirement will be approximately 100TB. This includes space for their SQL Server user database, system databases, temp database and log files and 7 days worth of SnapShots. We are going to propose using SMSQL to back up the SQL server instance. The FlexVol and LUN layout proposal is as follows:

<servername>_usrdb1: 12.68TiB, containing 1 x 11.16TiB LUN, for the .mdf file

<servername>_usrdb2: 38.05TiB, containing 3 x 11.16TiB LUNs, for the .ndf files

<servername>_usrdb3: 38.05TiB, containing 3 x 11.16TiB LUNs, for the .ndf files

<servername>_usrdblog: 7955GB, containing 1 x 7000GB LUN, for the .ldf file(s)

Other smaller FlexVols and LUNs for the tempdb and systemdb files

My question is, does anyone have experience with using SMSQL to SnapShot very large database LUNs and underlying FlexVols? The customer has concerns about SMSQL performance and time to complete the backup when backing up such a large SQL server instance. I'm expecting the performance of SMSQL, in terms of backup completion time to be the same as if I was backing up a much smaller database with the same LUN / FlexVol layout. Is this the case?

Thanks.

Greg Davis

NetApp PSC, ASEAN

[thomas_glodde]

hi there,

so far i only worked up to 3tb sql databases or 12tb oracle databases, backups work like a charm. i think backup time might increase a little due to the large ammount of transaction logs which needed to be copied over to the snapinfo disk. if the database is under extreme load vss quiescing might take a while or even fail.

Kind regards,

Thomas

[radek_kubka]

I think that backup verification may be also a bit problematic due to the amount of data which needs to be read.

Regards,

Radek

[thomas_glodde]

Verification can be offloaded to a different sql machine if needed. but the sequential read load on the storage remains, yes.

[radek_kubka]

...or even better - to a different SQL server on a DR site using SnapMirror target volumes for verification

[dgreg]

Hi Thomas and Radek,

Thanks for your emails. That's useful information, and a good point made about the transaction log copy process to SnapInfo - this is most likely going to have the biggest impact on SMSQL backup time. Verification may be best to push to the DR site, I agree since this solution will make use of SnapMirror as well.

Thomas how long did the actual SnapShot of a 12TB Oracle database take with SMO, assuming this was in one FlexVol?

Thanks.

Greg Davis

NetApp PSC, ASEAN

[thomas_glodde]

Hi Greg,

as the database wasnt a very stressed one, usualy we were within 3 to 5 minutes. Database was spread across a few flexvols, i think 4 or 5. Was red hat linux 5 64bit with oracle 11g using fcp.

Kind regards,

Thomas