Huge db backup taking too long. help me reduce

  • Ugh, the problems of having decenteralized job functions...

    I'm going to check on this, but based on a conversation I had the other day with the Sys Engineer from Corporate Systems, I thought we backed up to disk first.  Netbackup runs sql server backup commands via a sql server agent tool.

    I'm building a good list of items to get answers to. 

    Bob McC

  • I'll bet your backup is happening across the network. That's going to slow it down. If it's going straight to tape, that will slow it down even more. If it's going to a 'network disk', does that server have antivirus running?

    -SQLBill

  • Most of the suggestions in this thread have assumed that you have some control over how the backups are done.  If Netbackup is running things, you don't have any control.  I've never used NetBackup but a quick search of the web tells me it is capable of staged backups (disk-to-disk-to-tape) and multiplexed backups (not sure but I think this is like striped backup).  If this is true it is up to your Sys Engineer to get busy and figure out how to make it run properly.  Just tell them their fancy-schmancy enterprise backup software ought to be able to match the 1TB in < 2hr benchmark you can get from some software that only costs a few grand. 

    If you really want to be in control, you need them to provide you with a network share to hold your backups and then they can worry about backing up that share and leave your SQL server alone.  I've already fought that battle with our previous network admin, mostly by just killing his stupid client every morning I came in and found nobody could get any work done because the backups were still running.  (Requiring he reboot his backup server, tee hee!).  Of course with control comes responsibility, and it will be up to you to make sure the backup jobs run, old backups get deleted, etc.

    With a database this size you won't be happy with the standard maintenance plan wizard, and you probably can't use the default NetBackup configuration.  Are you waiting for a single-threaded client to move the entire contents of the database over the network to the tape drive?  That's not acceptable.  If you scaled the results I got (local backup to 4 local 15K RPM SCSI drives, assuming time scales linearly) your backup would be done in under 30 minutes and then it would take 3 hours to move it to the backup server, and you probably don't care how long it takes to get to tape.  If this can be managed by a NetBackup staged configuration then fine, otherwise it has to be done by SQL Server.

    How long will it take you to do a restore?  Call the Sys Engineer, wait for him to load the tapes, then wait 3 days to restore them?  Is this acceptable?  If you backup to disk, you can start the restore yourself immediately.

    What do you do if somebody says they screwed up one little table in your 780GB database?  If you used SQL LiteSpeed (or a competing product with the same object-level recovery feature) you could restore that one table right away, probably in minutes.  I don't know what business you're in or what 3 days of downtime would cost you, but I'll bet the backup software would pay for itself the very first time this happened.

  • I agree that you have to get back control of your backups. How much disk space do you have? If you have room to do the backups to disk, then do so. Use the SQL Server commands (or maintenance wizard) to do backups and then have your NetBackup people copy the backup file to tape or wherever they need.

    If you don't have enough disk, get your management to approve purchase of a large enough disk (or disks) and have it installed on your server.

    -SQLBill

  • And if you have a lot of space but not equal keep in mind these backups can be compressed easily. You can setup a compressed folder and store the backups there. Had a 50GB db that I backed up to a compressed folder on another drive nightly before it was picked for network backup. The file fit in 7-9GB of space on the D drive of the system very nicely.

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