Data Backup and Recovery

Another SMSQL question regarding "retainsnapofsnapinfo".

marcconeley
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A quick question which I hope someone can help me with.

I using SMSQL & running daily FULL backups at 00:00 every day and 18x hourly tlog only backups.

I want to keep backups going back 4 days.

Therefore I have 2 separate SMSQL jobs scheduled: 1 for the FULL backups (which include Tlogs also) and 1 for the hourly tlog only backups.

The SQL job params look like this:

TLogs params:          -RetainBackupDays  4 -lgbkonly -bksif -RetainSnapofSnapInfoDays 4 -trlog  -noutm  –mgmt standard

Full backup params: -RetainBackupDays  4 -lb -bksif -RetainSnapofSnapInfoDays 4 -trlog  -noutm  –mgmt daily

Now:

- By default a backup also forces a "snapshot of the snapinfo LUN" - this means that after every backup (whether it be a tlog or full) the vol holding the snapinfo LUN is snapshot! Is there a better way to configure this? Maybe only do volume level snapinfo snapshots once per day i.e. when my full backup runs & not after every tlog backup?

My problem is that the SnapIno LUN always has plenty of space and can hold 4 days of SQL backups no problems - but the volume snapshots didn't seem to get deleted when I was using the default "-RetainSnapofSnapInfo 8" command (it wasn't keeping only the last 8 - it was keeping more than 10days worth which eventually filled my volume). When this happens SMSQL doesn't generate an error as the backup worked - only the snapshot of the vol failed. Instead I get a Filer volume warning telling me my volume is 100% full.

The only option in SMSQL is to either turn "create snapshot of snapinfo drive after backup" on or off - which means after every hourly transaction log backup it also snapshots the snapinfo drive. Is this not overkill? I have 4 days of streamed backups on the LUN, then can I simply keep 1 day of snapinfo snapshots?? Why are the snapinfo snaps so important if we have the backups available on the LUN anyway?

I've read a great post about FR and SMSQL, but I can't find much regarding this "-RetainSnapofSnapInfo" and how it should be used when performing regular SMSQL backups.

Thanks,


Marc

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