Hi, 10.09.2007 00:51,, Ivan Adzhubey wrote:: ... > On a related issue: I have asked this question before but never get any > answer. > > Documentation states (from Data Spooling article): > > "While the spooled data is being written to the tape, the despooling process > has exclusive use of the tape. This means that you can spool multiple > simultaneous jobs to disk, then have them very efficiently despooled one at a > time without having the data blocks from several jobs intermingled, thus > substantially improving the time needed to restore files. While despooling, > all jobs spooling continue running." > > I have always had spooling enabled and the behaviour I observed through > several versions of Bacula (from 1.36.2 to 2.2.1) was never anything like the > described above. In reality, with simultaneous jobs enabled, several jobs > were happily despooling to the same tape drive simultaneously (until I take > countermeasures in the configuration to prevent this) wrecking havoc on my > tapes. I think the documented behaviour would make much sense and would have > prevented the MediaId bug from stricking. If only it would be actually > implemented...
My experience is quite different and fits the manual: While one job is despooling, all other jobs using the same tape drive are either spooling (no problem) or waiting for despooling. This is the case on Bacula versions from 1.38.something to 2.0.3 at least. I would suggest to turn on debug logging before the jobs start and trace what the SD does, until more than one job actually writes to tape. At a debug level that reports the device reservation process and actual block writes to tape, the resulting trace will might get really huge, though... Anyway, perhaps you can identify where the SD allows multiple jobs write access to the storage device - I found that I could understand the trace file quite easily. Arno > --Ivan > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users -- Arno Lehmann IT-Service Lehmann www.its-lehmann.de ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
