> With perfer mounted volumes on (default), as you know the algorithm will > always select a drive that is currently mounted, however, if I am not > mistaken, when no jobs are running and there are two drives with appropriate > Volumes mounted, it will attempt to alternate between them, and if there are > multiple drives actually writing, the algorithm will attempt to balance the > number of jobs on each drive (I didn't look at the code, and this last remark > may only apply if prefer mounted volumes is off). > I am not sure if this functionality has changed from 1.38.X (as I use the drives directly now) but what I saw was that with prefer mounted volumes on bacula would most of the time use the first drive when I selected the autochanger resource. If a job was running, a second job to a second pool would sometimes block instead of running on the unused tape drive. If no job was running, a job to a different pool than the tape in the first drive would cause the tape to be unloaded from the first drive and sometimes the tape needed was already in the second drive so it too was unloaded to put it into the first drive.
> > If you have prefer mounted volumes off bacula will pick any tape in the pool > > when running jobs. > > The algorithm for picking available Volumes from the correct Pool is in the > Director, and is totally independent of the state of prefer mounted volumes > and anything else that is going on in the SD ... > Sorry. My problem here is from time to time I have seen that bacula has 2 or more tapes with the Append status for a single pool which I find a little annoying. A way to avoid this I guess is not to have any unused labeled tapes in a pool and let bacula grab new tapes from either recycling or the scratch pool. > > I would say that both results are not what a user of a multitape changer > would want. > > Well that is an interesting remark. What does a user of a multiple "drive" > autochanger want? > To minimize tape swapping, maximize the use of the drives and to prefer to use tapes with the Append status over grabbing a new tape. One thing that might be different between my needs and others is that I never want to use more than one drive at a time for a single pool. I am not sure that made sense so I will try to say it a different way... I mean that if there are concurrent jobs running for a single pool I want this to only be on a single drive at a time. Thanks, John ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Bacula-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-users
