Kern Sibbald schrieb: > On Sunday 30 September 2007 11:05, Ralf Gross wrote: > > sorry if this may be more on topic on the users list, but I'd like to > > hear some developer opinions before I possibly create a feature > > request. > > > > I'm using spooling for all jobs. Now we are beginning to backup very > > large amounts of data (some TB) in a single job (I'm still looking for > > a good way to reduce the jobs size, but this seems not to be easy). > > > > These jobs will run for >24h, with spooling enabled it will even take > > longer. The current spooling implementation is good if many jobs are > > running concurrently, but I've only few jobs running in parallel, most > > of the time just one job. > > > > In this case it would help if spooling and despooling to tape could > > happen in parallel. With just one spool file per job this might be > > hard or even impossible to implement. > > > > What about multiple spool files? I can use 1 TB disk space for > > spooling, so bacula could use 4 250 GB files for each job. > > > > This is what I'm thinking of: > > > > 1. spooling to file1 > > 2. spooling to file2 and despooling the data from file1 to tape > > > > ...and so on. This will save time where the tape is idle because the > > job is spooling data. > > > > If spooling is much faster than despooling to tape and all 4 > > spoolfiles are in use, the job just waits until the next (first) > > spoolfile can be used again. > > > > I'm not that familiar with the spooling implementation and spooling of > > attributes is also involved. Thus I don't know if this idea will > > result in a complete redesign of the spooling concept or if it might > > be possible to just be added to the current spooling implementation. > > > > Any opinions? > > Some time ago, Eric and I discussed implementing the feature you request > because for users with really long running jobs like you, it could give a > significant performance enhancement in terms of total runtime of the job. > > At first, I thought it would be rather trivial to implement, but it is in > fact > a a medium size project rather than something trivial. I think it would be a > very good idea to implement multiple spool "directories" at the same time so > that the spooling can be more easily spread across several different disks > for even more performance improvements. > > The bottom line is that this is a project that is worth while, but IMO the > priority is much lower than a number of the other projects which are critical > to enterprise acceptance of Bacula. However, if someone would like to work > on this we would be happy to provide the appropriate guidance to ensure that > any patch developed would be accepted.
Ok, then it will be worth a feature request, even if it won't be on top of the projects list. Unfortunately I won't be the one that implements that feature, my C skills are not adequate for a project of that size. Ralf ------------------------------------------------------------------------- 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-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
