How do you set up RAID1 with both disks bootable on Debian/Ubuntu?

Solution 1:

I have done this before a year or so back to a few servers. It is a bit of a pain but doable. Its easier if you have hardware raid.

When I did it to a debian box I followed this awesome guide that saved me because there are many steps involved and it is a pain the arse if you get it wrong.

In short, you use mdadm to create your two partitions (md0/md1) (root/swap) do some copying on the guide, edit your boot menu do a few reboots and get the two drives in sync. Once you have them in sync you will be able to pull out each drive, and boot from it. Make sure you test it works though, and re-syncs the drives.