Moving /var, /home to separate partition

Reference: https://unix.stackexchange.com/questions/131311/moving-var-home-to-separate-partition

1. First you need some unallocated space to create the partitions for each mountpoint (/var, /home, /tmp).

2. Then you need to create the filesystems for those partitions, for example, to create a new ext4 filesystem on the /dev/sdaX device (replace /dev/sdaX with your own device):

 mkfs.ext4 /dev/sdaX

3. Mount the new filesystem under /mnt

 mkdir /mnt/var        
 mount /dev/sdaX /mnt/var

4. Go to single-user mode so that there is no rw activity on the directory during the process

 init 1

5. Enter your root password.

6. Backup data in var only (not the /var directory itself)

 cd /var
 cp -ax * /mnt/var

7. Rename the /var directory after your data has been transferred successfully.

 cd /
 mv var var.old

8. Make the new var directory

 mkdir var

9. Unmount the new partition.

 umount /dev/sdaX

10. Remount it as /var

 mount /dev/sdaX /var

11. Edit /etc/fstab file to include the new partition, with /var being the mount point, so that it will be automatically mounted at boot.

 /dev/sdaX       /var     ext4    defaults    0 0

12. Repeat steps 1-11 for /home and /tmp.

13. Finally return to multitasking mode.

 init 5