Long running backup after upgrading tp 7.31FC7X4

Hi, I have a problem where my backups have jumped from a 6-8 hour window to 18+ hours after upgrading from 7.30FC6 to 7.31FC7x4. I am using onbar with Legato Networker as the storage manager. I have really erratic backup behaviour. The backups go to four DLT7000 tape drives, and all four drives start writing at 10Mb/sec + (including hardware and software compression). However, after the first hour, the throughput to every tape drive drops dramatically. The OS is Tru64 V4.0D. Any suggestions gratefully received. Thanks, Paul.

Check the outputs of onstat -b and onstat -u when the slowdown occurs. I have seen similar symptoms where the archive started "writing" pages to disk, slowing down the archive (but not the normal-expected level of physical page "before copy" writes on the system). This (surprisingly) seemed to cause no corruption with the system. However, the system was using ontape. The problem was also highly intermittent on the system. Tech Support recognised the problem as a known issue. I'm not sure of the "fix release". If you see your archive threads doing frenzied writes (particularly if you have a "quiet backup window"), then you could expect the same problem. BTW - the Tech Support issue was with "archive incorrectly interpreting modification timestamps on pages". Brett Randall Frank wrote: > > Hi, > > I have a problem where my backups have jumped from a 6-8 hour window to 18+ > hours after upgrading from 7.30FC6 to 7.31FC7x4. I am using onbar with > Legato Networker as the storage manager. I have really erratic backup > behaviour. The backups go to four DLT7000 tape drives, and all four drives > start writing at 10Mb/sec + (including hardware and software compression). > However, after the first hour, the throughput to every tape drive drops > dramatically. > > The OS is Tru64 V4.0D. > > Any suggestions gratefully received. > > Thanks, > > Paul.

I have experienced the same problem when upgrading from 7.31fc2 to 7.31fc7 .The ontape archive took 3-4 hours while before it was max. 40 minutes.But with time ;I don't know how; it decreased to 1 hour.I think you could increase the blocksize parameter for the related tapedevice in onconfig, it would help. In article <3A539199.D8CD9061@hotmail.com>, Brett Randall <brett_s_rREMOVECAPITALS@hotmail.com> wrote: > Check the outputs of onstat -b and onstat -u when the slowdown occurs. > I have seen similar symptoms where the archive started "writing" pages > to disk, slowing down the archive (but not the normal-expected level of > physical page "before copy" writes on the system). This (surprisingly) > seemed to cause no corruption with the system. > > However, the system was using ontape. The problem was also highly > intermittent on the system. > > Tech Support recognised the problem as a known issue. I'm not sure of > the "fix release". If you see your archive threads doing frenzied > writes (particularly if you have a "quiet backup window"), then you > could expect the same problem. > > BTW - the Tech Support issue was with "archive incorrectly interpreting > modification timestamps on pages". > > Brett Randall > > Frank wrote: > > > > Hi, > > > > I have a problem where my backups have jumped from a 6-8 hour window to 18+ > > hours after upgrading from 7.30FC6 to 7.31FC7x4. I am using onbar with > > Legato Networker as the storage manager. I have really erratic backup > > behaviour. The backups go to four DLT7000 tape drives, and all four drives > > start writing at 10Mb/sec + (including hardware and software compression). > > However, after the first hour, the throughput to every tape drive drops > > dramatically. > > > > The OS is Tru64 V4.0D. > > > > Any suggestions gratefully received. > > > > Thanks, > > > > Paul. > Sent via Deja.com http://www.deja.com/