Re: NetApp flier - based snapshots and db backups -- CAVEATS

  • From: Hemant K Chitale <hkchital@xxxxxxxxxxxxxx>
  • To: amit.poddar@xxxxxxxx, oracle-l@xxxxxxxxxxxxx
  • Date: Sat, 21 Jul 2007 08:29:01 +0800

1. A Snapshot taken without BEGIN BACKUP is restartable _if_ the Online Redo Logs and ControlFiles are in the same snapshot with the datafiles. If Online Redo Logs in a seperate Filer Volume (QTree) and get snapshotted at a different point in time, then your database is NOT restartable. Snapshotting the RedoLogs and ControlFiles and DataFiles together is the same as "pulling" the plug.

2. What I would recommend and what NetApps recommends are Snapshots of DataFile volumes when in BEGIN BACKUP mode, followed by END BACKUP and a few SWITCH LOGFILE, ARCHIVELOG CURRENT
commands, and _then_ a seperate snapshot of the ArchiveLog volumes.
_THAT_ provides a Recoverable backup.
That is what I do on NetApp, EMC (except that CXs require SUSPEND/RESUME) , Hitachi ShadowImage
and IBM FlashCopy backups.

See documents TR3369.pdf
(funnily the version onsite is of Mar-06 while I can see on my desktop that I had, in Jan07, downloaded
a Dec-06 version of the same document)

and MORE IMPORTANTLY : TR3130.pdf at

Hemant K Chitale

At 05:21 AM Saturday, amit poddar wrote:
It would be like a shutdown abort copy right ?

i.e when started oracle would do a crash recovery since the snapshot includes online logs.

We can shutdown the database and then roll it forward

where am I going wrong ?

Closson, Kevin A wrote:
be aware that a database in a filesystem snaphot looks EXACTLY like it would if you pulled the electricity from the database server when Oracle was up and running. You cannot roll forward from such an image. NetApp documents all this quite well...just be aware that there is no magic ...

From: <mailto:oracle-l-bounce@xxxxxxxxxxxxx>oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Vasu Balla
Sent: Friday, July 20, 2007 10:24 AM
To: <mailto:vbarac@xxxxxxxxxxxx>vbarac@xxxxxxxxxxxx; <mailto:oracle-l@xxxxxxxxxxxxx>oracle-l@xxxxxxxxxxxxx
Subject: RE: NetApp flier - based snapshots and db backups

Oracle OnDemand, which hosts more than 1000 databases on netapp filers, uses this snapshot functionality for backup. you are not alone :)


Hemant K Chitale

"First they ignore you, then they laugh at you, then they fight you, then you win" !" Mohandas Gandhi Quotes :


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