Re: Speeding up RMAN backup using TDP

Hi Stefano

It looks like your I/O performance is very low(~75GB/hr with SQL backtrack),
I'd suggest looking into that first - perhaps by seeing if a disk-to-disk
copy can do any faster to help identify where the problem is.

For comparison, our HPUX Itanium servers with EMC SAN and RAID-5 can copy
disk-to-disk at about 300GB/hr.  At a previous site, a full level-0 RMAN
backup could do either 3 or 5 TB (don't have my notes on hand!) in 10 hrs -
this was Sunfire server with a dedicated Gb-ethernet LAN for backups going
to TDP with disk pool staging and around 6 tape heads.  The TDP server had
heavy contention for resources from other databases though.

But I'd suggest finding if/where the I/O bottleneck is  before bringing RMAN
into the picture.

There is also a very good Oracle whitepaper on tuning RMAN which helped me
to halve level-0 backup times.

Hope that helps...
Jeff Wong


On 3 July 2010 07:34, Stefano Cislaghi <s.cislaghi@xxxxxxxxx> wrote:

> Hello all,
>
> looking here for some tips on debug RMAN backup using TDP.
> Simply my RMAN backup is working, but is slow.
>
> My enviroment is using a TSM server that uses disks and not tape...this
> should be quite fast.
>
> Actually we're using a third party tool (BMC SQL Backtrack) to backup and
> this is doing for comparison 100Gb of DB in about 1h30m.
>
> My RMAN full backup using TDP for same 100Gb takes 3h.
>
> There's no RATE defined and restrictions on RMAN channel instantiation and
> in dsm.opt for TDP.
>
> Simply looking during backup my disks reading does not reach a speed up to
> 20MB/s.
>
>
> Any suggestions?
> Thanks
> Ste
>

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