On Fri, 27 Mar 2009, Larry Mascarenhas wrote:

> Hello,
>
> I'm running backups on Informix7 DBs. We're able to stream the DB
> backups using parallelism 4 and get good throughput (100MB/s, yes
> megabytes/sec, it is a SAN Media Server). A 300Gig DB takes less than 1
> hour.
>
> However (I know ;)), when it backs up the LOGS (all backups go to tape,
> I don't have Disk backups), each log comes in as a separate request.
> Each log is therefore a separate job. So the time taken to process this
> request is greater than the time to backup each log. ie each log is
> 100MB and the time taken is <2secs (when the resource is allocted and
> ready), but it takes 1+min to create the job/assign the resource/and
> begin writing. This is resulting in my never being able to catch up with
> the rate of logs generation although the amount to be backed up is
> minimal eg 30logs is just 3Gig, but takes approx 30mins and by that time
> 10 more logs are created. I am using media_unmount_delay so the tapes
> are not re-mounting for every request.
>
> I cannot increase the size of the LOGS as this would affect replication
> and recoverability (double whammy). This is Symantec's recommendation.
>
> I'm looking for experiences that people have had to speed up the
> Informix backups.
>
> Thanks.
>
> -- 
>
> Larry Mascarenhas
> LMascare AT comcast DOT net
> _______________________________________________
> Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
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>

Why not use a Disk Staging Unit if the logs are small enough?

Send to disk first -----> then shoot to tape?

Justin.
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