On 03/29/10 01:48 PM, Kern Sibbald wrote: > On Monday 29 March 2010 12:48:14 James Harper wrote: >>> In addition, one should take care in using multipe disk Devices that >> >> write to >> >>> the same physical disk drive. Depending how you set it up and how >> >> many you >> >>> have, you may create severe disk fragmentation and performance >> >> problems. >> >> >> I use 1 disk device per client (and 1 job per volume) and had never >> considered that fragmentation could be a problem... In retrospect I >> guess it was pretty obvious. > > For most people, it may not be so obvious, but for someone like me who thinks > about Bacula all the time (too much), it is a concern. > >> xfs_db tells me I have 99.94% fragmentation >> - I guess it couldn't get much worse :) > > Yes, I have recently run into a case, where one site is trying to > simultaneously write to 120 different disk devices. IMO, this is a far from > optimum Bacula configuration.
We'll top 300+ devices per SD once we are finished migrating. > Some sites for reasons of security or separation of data may need to use a > different disk device per client, and that will work fine until you get up to > 50 or 100 clients, then the performance problems will begin to show up. This is *highly* dependent on your underlying filesystem and / or storage subsystem. >> >> Backup performance isn't an issue at this time but it's something to >> think about in the future. > > Bacula permits sys admins to configure it in many different ways -- it is very > flexible which is good, but can also lead to bad configurations. However, as > backup jobs get larger and larger over the years (bigger computers, ...), and > the number of users increases, configurations that previously worked well > will no longer serve. Unfortunately, because the project is much bigger, > certain developer's such as my self are no longer able to provide this kind > of support, but I think that more experienced people who are on the > bacula-users list can help a lot, and there are a good number of those > experienced users willing to help. > > Best regards, > > Kern > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Bacula-devel mailing list > Bacula-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-devel -- Med venlig hilsen / Best Regards Henrik Johansen hen...@scannet.dk Tlf. 75 53 35 00 ScanNet Group A/S ScanNet ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Bacula-devel mailing list Bacula-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-devel
