Jesper Krogh schrieb: > > Item n: Concurrent spooling and despooling withini a single job. > Date: 17 nov 2009 > Origin: Jesper Krogh <jes...@krogh.cc> > Status: NEW > What: When a job has spooling enabled and the spool area size is > less than the total volumes size the storage daemon will: > 1) Spool to spool-area > 2) Despool to tape > 3) Go to 1 if more data to be backed up. > > Typical disks will serve data with a speed of 100MB/s when > dealing with large files, network it typical capable of doing 115MB/s > (GbitE). Tape drives will despool with 50-90MB/s (LTO3) 70-120MB/s > (LTO4) depending on compression and data. > > As bacula currently works it'll hold back data from the client until > de-spooling is done, now matter if the spool area can handle another > block of data. Say given a FileSet of 4TB and a spool-area of 100GB and > a Maximum Job Spool Size set to 50GB then above sequence could be > changed to allow to spool to the other 50GB while despooling the first > 50GB and not holding back the client while doing it. As above numbers > show, depending on tape-drive and disk-arrays this potentially leads to > a cut of the backup-time of 50% for the individual jobs. > [...]
I'm also very interested in this feature. http://thread.gmane.org/gmane.comp.sysutils.backup.bacula.devel/10589/focus=10593http://thread.gmane.org/gmane.comp.sysutils.backup.bacula.devel/10589/focus=10593 We are backing up mostly large files, so writing directly to tape over the network is possible with 75 MB/s. Using fast disks for spooling our LTO-4 drives can write to tape with ~130 MB/s (the files are already compressed). But sometimes when writing to tape without spooling the rate drops down below 40 MB/s which is when the tape drive starts shoe shining. So we want to be on the safe side and use spooling for all jobs. For these jobs it would be nice to have something different that spooling (as it works now), just a simple buffer (FIFO) that fills up and then writing to tape begins. Ralf ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Bacula-devel mailing list Bacula-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-devel
