> What would be the best path to follow? Mirror the whole disks and put > all the partitioning onto the md0 device? Or create partitions on both > disks independently and then pair these up in RAID? At what level is it > best to introduce LVM?
For _GRUB1_ configurations my typical suggestion is: /dev/sda1: /boot (1) /dev/sda2: [swap1] /dev/sda3: MD-dev1 /dev/sda1: /boot (2) /dev/sda2: [swap2] /dev/sda3: MD-dev2 MD-dev1 and MD-dev2 are combined into a RAID1, this /dev/md0 is used as a physical volume for LVM. /root is a logical volume. System boots from (and mounts) one of the /boot volumes, the other one is unmounted. rationale: a) GRUB1 can't boot a LVM-volume, therefore a non-LV /boot (or root) volume is required b) it is unwise to put (all) swap into LVM-volumes because a deadlock can occur if memory gets really tight This setup is _not_ 100% automatic - someone has to copy the contents of the mounted /boot filesystem to the backup filesystem - the MBR must be copied to the backup disc - one of the discs may fail and cause loss of the swap space's content The swapspace issue may be circumvented by raid1-ing the swap device too. But then again: A system that is using the swap space is probably close to un-usable anyway. (Except if swap-space is pre-allocated like oracle does.) GRUB2 can boot a LVM-Volume. It might be possible to drastically simplify this setup.
