Re: Backing up large DBs on ASM
Date: Tue, 23 Jun 2009 17:04:46 +0200
You didn't say, but I'm assuming when you say you're backing up to "tape" -- they're probably VTLs. In other words probably SATA disks or some other type of cheaper disk that your backup software presents as a tape.
What you can also consider, is adding those disks to your ASM, and keep a copy of the database in there. This has many advantages:
- You don't take traditional backups anymore, you only take incrementals to recover the copy
- Using BCT, those incrementals become very fast -- size of the database doens't really matter anymore, only how much of its data changes is what matters (regarding the time needed for backups)
- In the event of datafile loss or failure in your primary datafiles, you simply switch to the copy -- the MTTR speed of that recovery method beats even the fastest backup SANs
- For added security, you can even dump the copy to tape once a week or so
In most cases, the disks are already there, you just need to "use" them differently, to get the most out of them
If you need additional information about this concept (I'm using it successfully for many clients) -- feel free to contact me off-list.
Stefan P Knecht
CEO & Founder
10046 Consulting GmbH
Cell +41 (0) 79 571 36 27
On Mon, Jun 22, 2009 at 4:50 AM, Hameed, Amir <Amir.Hameed_at_xerox.com> wrote:
> One of our large client has a very large DB (~40TB) configured with ASM.
> They are currently using RMAN to back it up to tape and it takes a very
> long time to do that. They have also tried backing up to disk but the
> timing has not really improved much. What they are looking for is ways
> to speed up the backup and restore timing. I am not directly involved
> with this client and do not have extensive experience with ASM and RMAN
> either. Are their any ways and best practices to speed up backups on ASM
> for very large DBs. Any feedback will be greatly appreciated.