Weasel disk partition plan

Currently I have two partitions, root and big. They are both managed by lvm and look like this:

root@weasel:/boot# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/Ubuntu-root
                      224G  107G  106G  51% /
/dev/mapper/vg00-big  230G  187G   32G  86% /big

It would be much more reasonable to have a small root partition that is easily backed up and separate partitions for /home, /store, and /big.

/store is a shared network-accessible space. /big is used for automatic backups of root, /home, and /store.

Partition	Size
root	4G
store	99G
home	3.4G
var	1.2G
big	187G

root is 107G (root + home + var + store), so if I would split them apart, root could be as small as 4G.

It would be handy if the root partition could be kept small enough to be backed up on a DVD.

So the new scheme would have 4 physical volumes:

Device	Size	Use
/dev/hda	250G	root, store, home, var
/dev/hdb	250G	big, network storage
/dev/hdc	500G	root backup
/dev/hdd	500G	big, network backup

The main idea is to partition disk failures, so I don't want to bunch all the disks together into a single volume group. When one disk goes bad, I don't want to lose access to part of another disk just because it is in the same volume group. I'm assuming that a volume group will fail when any physical volume in that group fails.

The logical volumes should be divided into primary and backup volumes and the sizes of the two volumes should match.

There should be a primary root, store, home, var, big. And there should be an equivalent backup root, store, home, var, big.

There should also be sufficient unformatted space in the primary volume group for a snapshot of the root partition so that an image can be taken and stored offline.