Backing up a Linux (or Other *nix) System

bigsmoke writes "My buddy Halfgaar finally got sick of all the helpful users on forums and mailing lists who keep suggesting backup methods and strategies to others which simply don't, won't and can't work. According to him, this indicates that most of the backups made by *nix users simply won't help you recover, while you'd think that disaster recovery is the whole point of doing backups. So, now he explains to the world once and for all what's involved in backing up *nix systems."

A quick reply from the author of the article

[halfgaar]

Hi there,

A quick reply from the author of the article before I go to sleep:

About dump. So, that's a freebsd command? I've always suspected it existed, doing the very thing the man page described, because of the dump field in /etc/fstab. But I have never actually seen a machine which had the dump command... It's possibly not very safe BTW. If it works like DOS's Archive bit, than it can't be trusted: it can be set manually. Some DOS apps even used them as copy protection mechanism...

The suggestions (for software and the rest). The comments are very much appreciated. I'll investigate them and adjust the article accordingly. For now, I have to sleep :)

One more thing

[halfgaar]

Oh, one more thing, encryption. I was in doubt whether to include it or not. I use different encryption schemes for my backups (LUKS for external HD and GPG for DVD burning), but I decided this can be left to the reader. I may include a chapter on it, after all.

Re:Consistent backups

[Just Some Guy]

The '-L' option to FreeBSD's dump command makes an atomic snapshot of the filesystem to be dumped, then runs against that snapshot instead of the filesystem itself. While that might not be good enough for your purposes, it's nice to know that the backup of database backend file foo was made at the same instant as file bar; that is, they're internally consistent with one another.