LVM

reduce logical volume

You must get a blank output from this command as below

lsof /home

Next un-mount the partition umount /home

check filesystem e2fsck -flinux show file syste /dev/mapper/arch-home

resize file system resize2fs /dev/mapper/arch-home 20G

reduce logical volume

lvreduce /dev/mapper/arch-home -L 20G

increase logical volume

lvextend -L +44G /dev/mapper/arch-root

resize2fs /dev/mapper/arch-root