Migrate /home to another physical drive

Question

I recently cleared about 500GB of junk from my HDD. Since I'm pretty low on space on my Arch install, I figured I'd dedicate 200GB of that to /home. Problem is that my /home partition is located on my SSD, not the HDD. I'm not sure how I'm supposed to migrate /home to another drive.

The partitions

_{(source: cubeupload.com)}

Recovery, EFI, Windows Boot, Arch Root Partition, Arch /home Partition and 20GB overhead for the SSD. The HDD is just a big dumping ground.

What I want is to move the /home partition safely over to the HDD (new 200GB partition), then merge the old /home with the root partition to create a bigger root partition.

Answer 1

Like UVV wrote in a comment, this shouldn't present a problem. Do it from single user mode if you want to play it safe.

1. Create a partition to hold the new /home, create a file system on it, and mount that file system.
2. Move everything under /home into the root of the file system on the new partition. mv /home/* /mnt/ or something like that should do nicely. Watch out for dotfiles! ls -A is your friend here.
3. Amend /etc/fstab to name the new partition for a /home mountpoint. I recommend you use a stable identifier; something under /dev/disk/by-id or /dev/disk/by-label should work nicely.
4. Make sure /home on the root file system is empty, mount /home and make sure it's populated, reboot and enjoy.

This is the upside of *nix systems separating mount points from the physical and logical disk layout.