AARGH! I am sooo close. Here's my setup:
Dell D630 with an internal 250GB drive, and a 120GB external USB drive.
/dev/sda1 XP (I back it up after booting to Acronis TrueImage Home 11 and connecting a USB drive)
/dev/sda5 Data1 (ext3, 100GB)
/dev/sda6 Data2 (ext3, 50GB)
/dev/sda7 M7Home (ext3, 5GB, for Mint 7 "/home")
/dev/sda8 M7Root (ext3, 10GB, for Mint 7 "/")
/dev/sda10 M6Home (ext3, 5GB, for Mint 6 "/home")
/dev/sda11 M6Root (ext3, 10GB, for Mint 6 "/")
/dev/sda12 (ext4 so no label, 5GB for Kubuntu 9.04 "/home")
/dev/sda13 (ext4 so no label, 10GB for Kubuntu 9.04 "/")
I'm trying out the techniques described in this thread, but backing up to Data1 for now (I'll rsync that partition to the external USB drive). I boot up with RescueCD v1.1.7 and create directories under "/A/" for all points. For example, /A/K9Home, and so on, and then mount them.
I can use the tar command for /A/K9Home to /A/Data1/K904/K9home_backup.tar.gz and /A/K9Root/boot to /A/Data1/K904/K9boot_backup.tar.gz. I'm stuck trying to tar up "/" though. I keep getting kicked back with "zsh: no matches found: --exclude=/A/K9Root/tmp/*. Here's the command I'm using, straight from your examples:
root@sysresccd /A/Data1/K904 % tar --one-file-system --exclude=/A/K9Root/tmp/* --exclude=/A/K9Root/dev/* --exclude=/A/K9Root/proc/* -pzcvf K904root_backup.tar.gz /A/K9Root
I've also tried that with a trailing slash at the end for "/A/K9Root/".
I run ls on /A/K9Root/tmp and it's there so I don't understand why the --exclude is choking on it. I have a lot of partitions so I can try out various versions of Mint and Kubuntu. I'm about to blow away the Mint6 stuff, but I'd like a backup just in case. I'd also of course like a backup of everything else. Previously, I was booting the rescueCD and rsyncing each partition to a like partition (with Data1 and Data2 not being the same size of course) on the external 120GB USB drive. I thought I'd try this technique, creating TAR balls on Data1 so I could just rsync Data1 to the external drive and have the stuff handy in case a partition went tits up.
Can you explain why I'm having so much trouble backing up "/"? Is it because it's ext4 perhaps? I'll try doing it with the Mint6 root partition, which is ext3, and see how that goes.
UPDATE: Nope. Doesn't work for Mint 6 either. If I remove the tmp option, it chokes on /dev. I try --exclude=/tmp/* and --exclude=/A/M6Root/tmp/* (thinking since I'm booted to the RescueCD, I need to give the explicit path to the /tmp directory in the Mint 6 partition. But no go.
I'm officially stumped. I guess I'll go back to rsyncing all of the individual partitions to the external drive for now.