I've identified some things... despiting some problems network related ... I'm able to see that - Max I/O for a single datafile is about 15MB/s per channel, allocating 4 channels I can reach about 80MB/s in reading - Previous backup was done using BMC SQL Backtrack that permits to have a 76% of compression and use 'BACKUP AS COPY INCREMENTAL LEVEL = 0' So I'm sure that BMC SQLBacktrack takes less time to backup as with a better compression level has less data to send to TSM Is not clear why using a single channel I can't reach the same reading performance as four channels... This seems not related to network or local I/O... may TSM be limited in incoming bandwidth? Ste On 9 July 2010 12:50, ~Jeff~ <jifjif@xxxxxxxxx> wrote: > 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 >> > > -- http://www.stefanocislaghi.eu