I have a 320GB hard drive with an LVM2 volume group that was created as part of the default installation. If I put a second 320GB hard drive into the computer, can I make the second drive mirror the first using Linux software RAID1 or something similar? I tried adding a new RAID array in the Gnome Disk Utility, but it only gave me the option of creating an array with two empty partitions.
Firstly, you should backup your data just in case.
Ok, at this point you should have a raid1 with all the correct information. Now you should configure your grub2 configuration, fstab, etc. Make sure you have all the correct kernel modules etc. Once this is done, turn off the computer, and physically disconnect drive0 (sda). Now, get the system up and running with md0 alone.
Once you have the computer fully operational without drive0 connected, turn it off again, and reattach sda.
I achieved this by backing up all of my data onto an external drive, reinstalling Ubuntu onto a raid array, and then restoring my backup in the new file system. In particular, I followed these steps:
I prefer this method for a few reasons: