On Sun, Mar 02, 2008 at 05:51:06PM +1300, Mark Kirkwood wrote: > I wrote: >> >> >> If you want to back the system up while it is running (in particular /), >> then you need to use a tool that understands how to create a backup image >> that is valid (i.e will boot) - something like xfsdump, *dumpe2fs* etc or >> smart tar/dump based tools like Amanda. > Hmm - dunno what I was thinking there - 'dumpe2fs' is completely wrong, > should have written 'dump', sorry!
If you do backup live filesystems/data then dump is on par with dd; both read from the underlying device and might bypass the kernel's page cache. Ie., there might be unwritten data cached thats not on disk yet. Tar/rdiff-backup/etc reads through the pagecache and avoids this problem. The dump people talk a bit about this themselves on http://dump.sourceforge.net/isdumpdeprecated.html Note I dont want to dis dump, backing up live filesystems is just tricky (depending on your consistency requirements :) and dump adds another level to that. Cheers, Rasmus -- gentoo-user@lists.gentoo.org mailing list
