Sorin Srbu wrote:

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I've never had any problems with software raid5 in linux before, but you never know...

There's a big write performance hit from raid5 (software or not). It may not be enough to be a showstopper but I wouldn't recommend it. Can you reconfigure to a 0+1 or some other type that has better performance without losing too much space? The archive does have to be on a single filesystem, though, and if you use the epel RPM it makes things easier if you mount the volume at /var/lib/BackupPC before the install. See 'how to change archive directory' from: http://sourceforge.net/apps/mediawiki/backuppc/index.php?title=Tips_and_Tric... to do it after the install.

I know, but in linux it's still a lot better than Windows, which I today regret I ever introduced it in... Don't get me wrong, reliability is fine, but the recheck on every restart is kinda' bothersome and takes like forever

Today I have five 500GB-disks raided on linux machine. Remove one for parity and I have 2TB of real space available. Doing a 0+1, ie 1TB, would indeed be better as performance goes, but 1TB of space, well, it just isn't enough unfortunately.

If you have any opportunity to change things, I'd get some larger drives and use raid1 or 0+1. If you want offsite copies, a workable approach in the 2TB scale is to make a 3-member raid1 where you periodically swap the 3rd drive (in an internal or external swappable sata enclosure). If you don't need that, a 4 drive 0+1 raid of 1.5 TB drives would give you 3TB and better performance. What you have will work - but it will limit performance.

As it is now, the 2TB shebang is mounted as /backup. Does that count as a single filesystem?

Yes, but if you use the epel rpm, either mount it at /var/lib/BackupPC or put a symlink there before the install. If you install from the sourceforge source there is an install script that modifies the location so you can put things where you want, but the rpm packages have already done that. The next version will make this easier to change but the current one needs to stay in the location set when the package was built.