On Tue, Nov 26, 2002 at 02:13:18PM -0500, Joe Nahmias wrote: > > I found the mail I alluded to before. It is also from linux-kernel... > You can see it at: http://old.lwn.net/2001/0503/a/lt-dump.php3 > He seems to say that you can get a corrupted backup regardless of > whether you use CD-R(W) or not. > An excerpt: > ==== > Note that dump simply won't work reliably at all even in 2.4.x: the buffer > cache and the page cache (where all the actual data is) are not > coherent. This is only going to get even worse in 2.5.x, when the > directories are moved into the page cache as well. > > So anybody who depends on "dump" getting backups right is already playing > russian rulette with their backups. It's not at all guaranteed to get the > right results - you may end up having stale data in the buffer cache that > ends up being "backed up".
May you should lvm a chance :) with lvm you can: 1) temporaly shutdown services that could change filesystem, eg mysql, after that create a snapshot of the filesystem. 3) start your services again 4) make backup of the snapshot. Read lvm-howto for further information. I personally haven't tried this, but it should work. > > > > Gerald Livingston wrote: > > > On Mon, 25 Nov 2002 20:08:53 -0500 (EST) [EMAIL PROTECTED] (Joe > > > Nahmias) wrote: > > > > > > > > >> Chris, > > >> > > >> Correct me if I'm wrong, but I thought Linus himself said that > > >> using dump on live (mounted) filesystems was a bad idea. I'll see > > >> if I can dig up a reference to it... > > > > > > I did a quick search: > > >http://search.alphanet.ch/cgi-bin/search.cgi?max_results=10&type=long&msgid=20011010173449.Q10443%40turbolinux.com&domain=ml-linux-kernel > > > > and found this email in the Linux kernel mailing list archive: > > > > > Andreas Dilger <[EMAIL PROTECTED]> wrote: > > >> > > >> Yes, but the only issue is if the filesystem is busy, you may get a > > >> bad backup for those files that have changed, but not for any > > >> files that have not changed during the backup. > > >> > > >> Reasons for not using tar or cpio include atime change and the fact > > >> that an "incremental" tar can't record the deletion of a file > > >> (AFAIK). > > >> > > > > I have not had any problems, but I am backing-up a home standalone PC > > and I do not multitask during the backup, so no files change during the > > backup. It would seem safest to boot into a second copy of Debian and > > run 'dump' from there. I do this for the large system backup anyway. > > > > Perhaps the 'changed file' problem is only an issue with 'cdbackup'? > > Presumably it would be accessing files during the backup process. In any > > case, backing up directly to CD seems to pose a much greater risk of > > backup corruption. > > > > Cheers, > > > > Chris. > > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] > -- Best regards, Alexey Chetroi --- Smile... Tomorrow will be worse. (c) Murphy's law -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
