Can I replace disk containing /home without reinstalling Ubuntu?

Question

I have formatted my hard disks so that /home sits in one separate disk. Now that disk has become faulty. I am wondering whether it is possible to replace only that disk and make a new /home partion on a new disk, so that I can avoid a complete reinstall of the OS? (I know that almost all my user data will be lost)

Answer 1

Answer is yes, you don't need to re-install OS. You can create a new partition (block device like /dev/sdb2) and use it for /home. You can also copy the data in old /home over if you have a good backup or the old home is still readable.

In your case, it seems that the old /home (disk) became faulty. You want to use a new partition or new disk for /home. It is fine and you don't need to re-install the OS.

Steps in brief (recommend doing this using a LIVE CD, you don't HAVE TO though):

1. create partition for /home
2. create file system, e.g. ext4 mkfs.ext4 /dev/sdb2
3. mount it as /home, e.g. mount -t ext4 /dev/sdb2 /home
4. mount your old home if it is still mountable, e.g. mount -t fs_type /dev/sdaX /mnt/old_home otherwise you'll have to restore data from a good backup
5. Use rsync to copy data, e.g. from a backup mounted as /backup/home rsync -axHAX --progress --verbose /backup/home/ /home
6. Remember to edit your /etc/fstab and update the block device/FS for new /home

Reboot and you should be good.