Re: [gentoo-user] backup to a cold-swap drive

[Alex Schuster]

Iain Buchanan writes:

> A winblows colleague said he uses a utility to backup his internal hard
> drive to an external disk, such that if his internal disk fails he can
> replace it with the external disk and continue straight away.

I do the same, but with a 2nd internal drive. The drive is partitioned 
similar, with some partitions being a bit larger so I can do incremental 
backups, too.

I am using rdiff-backup, which makes use of rsync. The backup partition 
has exactly the same contents as the source partition, except for an 
additional 'rdiff-backup' directory that contains incremental backups of 
files that were modified from backup to backup, gzipped.

Some other partitions are handled differently: /boot is just being dd'ed, 
contents of /usr/src are tarred each, and /var/portage/packages/ is just 
plain rsynced. Some unnecessary stuff like .ccache and /var/tmp/portage is 
excluded.

All my partitions are LVM volumes, so before the backup starts, I make a 
LVM snapshot of the partition. This way I can modify it while the backup 
is still in progress.

I wrote a shell script to do this, so I do not have to issue a lot of 
commands every time I want to do the backup. As there are now some others 
using this script, adapted to their needs, I started to rewrite it in a 
way that it reads a config file, and no modification of the script itself 
is necessary. If anyone is interested, send me an email.


Some time ago my first drive started having bad blocks. Without LVM, I 
could just have swapped the disks, but so I had to rename the backup 
volume group to the original volume group from a live cd. And the system 
was running from the new drive as it was before - only that I no longer 
had a backup until the new drive arrived. This makes an uneasy feeling 
with these 1.5 TB drives.

	Wonko