From: Graham K. <gr...@eq...> - 2011-01-28 10:38:39
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On Thu, Jan 27, 2011 at 12:57:45PM -0500, Phil Stracchino wrote: > The best plan for managing disk volumes, IMHO, absent other constraints, > is to allow the disk to contain as many volumes as it has physical room > for, allow each volume to be whatever size it needs to be to hold the > jobs you're writing to it, and make sure that all the jobs written to > any single volume all expire at roughly the same time, so that there's > only a few hours between when jobs start to be pruned off the volume and > when the entire volume becomes available for purging and deletion. The > way to accomplish this is to use different Pools for different retention > periods (which usually maps very closely to backup levels), and limit > the time during which each volume is writable. Which brings us back to > Volume Use Duration. Thank you for this idea. I have not seen it before in any documentation. I asked Kern about "best setup for backup to disk" in November, and was told that he might have some white papers that covered some of my points and that he'd be happy to improve them, but I needed to be an Enterprise customer to see them. Three concerns about your idea: a) If one client out of the four that were backing up that night went crazy because of your hypothetical _Cheers_ download and used most of the disk space, then you have no way of isolating and purging that "bad" backup because it is entwined with the other three "good" backups. You either have to live with it, or throw away the lot. b) It doesn't address the problem of managing your disk space. In my original post to this thread, I was wanting to limit the amount of space that bacula uses. This was probably not clear, because I then started talking about the size of the disk. How would I say - "bacula should limit itself to 500GB"? > Disk volumes *are not a finite quantity resource*. You're not going to > run out of slots for them. You're not going to run out of labels. > There is no reason to limit how many of them you can have, as long as > you have disk space for them. > > *This* - the mistaken idea that you can inherently only have just so > many disk volumes - is the invalid initial assumption that is screwing > you up. c) Since you started this thread by explaining that having lots of small volumes is going to cause you problems, I'm not convinced. |