Re: Tuning RMAN backup and recovery

On Nov 26, 2007 4:49 PM, Don Seiler <don_at_seiler.us> wrote:
> Also one bit of sadder news. I performed an RMAN duplication the
> Friday before last that took over 25 hours. However I really don't
> want to even start any kind of diagnosis until we at least move RMAN
> storage to different disk.

Well I'm in the midst of another insanely-long duplication. The /rman on the auxiliary server is indeed on the same spindles as the rest of the datafiles, but I thought I'd ask anyway.

The recovery process is going through the "cataloged datafile copy" for each datafile in the instance. Messages like this:

cataloged datafile copy
datafile copy filename=/u10/oradata/stage/txbill_idx13.dbf recid=210 stamp=640430010

However, each of these take 3-4 minutes, judging by the duplication log updates. When I have hundreds of datafiles, 3-4 minutes each is an incredibly long time. Nothing is being written to the aux instance alert log during this period.

It seems that since we moved production to 64-bit hardware, this duplications went from 9-10 hours (which I thought was way too long) to 25-26 hours (which is a horrible joke). I'm going to pour over some of the online guides and Robert Freeman's 10g RMAN book. If anyone has any tips or cluebats, swing away.

-- 
Don Seiler
http://seilerwerks.wordpress.com
ultimate: http://www.mufc.us
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