Hello, On 9/4/2006 11:17 AM, Ferdinando Pasqualetti wrote: > How big is your backup? If it fit completely in the spool area the > behavour seem lead to the fact tha your bottleneck is the tape throughput. > Backup rust faster to the spool area, but the tape writing take the same > time. > I believe that spooling only gain performance when the FD cannot feed > enough data to keep the tape streaming (typically during an > incremental/differential backup), otherwise direct writing is faster.
Or to allow multiple jobs running simultaneously and still keep jobs in larger chunks on tape. > Too > bad the disk-to-tape operation of spooling is done suspending the > backup-to-disk operation (no concurrency with double buffering) and this > limits the usefulness of spooling (as far as I know). Well, it is a certain limitation, although I don't see huge gains if FD-SD-transfer continued while SD-tape-transfers run. First, this would require much more throughput to the disk system which more often than not already is a limiting factor. Second, assuming the despooling to tape is actually faster than spooling from the FD, an overall gain would be small because in many cases the despooling would still have wait. Anyway, I guess that job migration will allow more sophisticated setups using D2D2T schemes to tweak the backups for maximum performance. Back to Gabrieles problems: When a server restart fixed the ongoing problems it might be worth running the DIR with bedug output enabled so you can see what actually happens behind the scenes when the problem happens again. Keep in mind that running with a high debug level will gerenate big debug output files, so I'd recommend to start with a level of zero and increase the debug level once you see the problems again. Arno > -------------------------------------------------------------------------- > Ferdinando Pasqualetti > G.T.Dati srl > Tel. 0557310862 - 3356172731 - Fax 055720143 > > > > > > > Gabriele Bulfon <[EMAIL PROTECTED]> > Inviato da: [EMAIL PROTECTED] > 04/09/2006 09.35 > > Per > bacula-users@lists.sourceforge.net > CC > > Oggetto > [Bacula-users] Spooling > > > > > > > Hello, > I worked with Bacula spooling to see the effects on Sparc 280R machines > (that continue to work very slow without spooling, almost 1000K/s). > I tried with different spooling dimensions (10Mb, 100Mb, 250Mb), the > result was almost the same: during a single job backup, speed increased to > almost 5000K/s. > BUT : at the end of the job, a final step of Bacula (kind of spool > flushing) last a lot of minutes, and during this step, the medium transfer > rate decreases. > The final result is then again a medium of 1000K/s... > > How should I size the spooling dimensions? Is there any way of calculating > the correct size? > What is that last step lowering the total rate? > May I assume that having 2-3 long jobs, this last step well have a little > influence on the total rate? > > > Gabriele Bulfon - Sonicle S.r.l. > Tel +39 028246016 Int. 30 - Fax +39 028243880 > Via Felice Cavallotti 16 - 20089, Rozzano - Milano - ITALY > http://www.sonicle.com > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job > easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users > > > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users -- IT-Service Lehmann [EMAIL PROTECTED] Arno Lehmann http://www.its-lehmann.de ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
