It's an awfully good question, but there probably isn't a single right answer. My server is a quad-cpu beast on a gigabit network, but I settled on two backups at a time after measuring degradation (first back up one at a time, then two, then three...) Then again, neither my file system nor server is dedicated, and for me, that means that other I/O bound processes don't have trouble running.
Naturally, your I/O wait will be higher if your CPU's are faster, and load average can be nonsensical if you're significantly I/O bound -- so I'd recommend doing something similar to what I did -- namely, try one backup at a time, then ratchet up the number until they slow down too much. Filesystem type and physical storage structure are significant in how much I/O overhead you've got. > The discussion over the various BackupPC scenarios got me to > thinking. My server IS disk bound. All the servers it backs up on on > at least a 100M network link in the same room and some on 1G. With > the default settings (4 simultaneous backups), the system is sitting > right now at load average 9.25 and IO/wait from 33-99%. How does one > best determine the fastest way to configure for the given scenario. > Based on one respondent's comments, it makes me think I might be > better off having only 1 backup running at a time? > > What's a good IO/WAIT average to shoot for? Load average? Other > things I might not be thinking of? > > Thanks in advance, > > James ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
