On Tue, Nov 10, 2015 at 11:24 AM, Chuck Anderson <[email protected]> wrote: > On Tue, Nov 10, 2015 at 12:06:03PM +0000, Edward Ned Harvey (blu) wrote: >> If you want to backup the entire filesystem in such a way that all the above >> is unnecessary - you instead boot from rescue media, partition & format the >> hard disk, and simply run "restore" and boot back into the restored system >> as if no problem had ever occurred, then assuming you're using ext >> filesystems, you need dump & restore. (Or you need storage on some >> snapshotting storage system external to the system you're restoring.) > > According to Ted Ts'o (filesystem developer), it is NOT a recommended > way to backup your filesystem: > > http://www.gossamer-threads.com/lists/linux/kernel/1197768 > > "It does read the mounted block device directly, and so it's certainly > not a _recommended_ way to back up your ext4 filesystem. It should > work, though, since it just uses the high-level libext2fs functions > --- and a while back, I think I did a quick test and found that it > really did work. So I'm not sure what broke, but it might not be that > hard to fix. That being said, it may not be worth it to fix it, since > with delayed allocation, backups using dump will be even more > unreliable than they were before. " - Ted Ts'o
Note that this is from 2010 AND it was for a live (mounted filesystem). I've used the rsync method myself to copy a system disk, but I've always been worried that if I didn't get the options just right I might lose an ACL or some other extended attribute and not know it. "Runs fine" doesn't mean some subtle problem (possibly security related?) hasn't been created. For stuff in /home, I worry much less about this and see no reason not to use rsync. I'm about to add an SSD to a system with an HD and I'm going to give "dump | restore" a try. One interesting feature of the Linux dump is that you can specify inodes not to backup and if it is a directory the whole subtree will not be copied. The system in question has /, /var, and /home all on one partition and I'm going to split them up in the new configuration so this will be helpful. /home is going to stay on the HD while / is moving to the SSD. Not sure about /var yet. Bill Bogstad _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
