Assume we have 2 partitions: /dev/fedora/root and /dev/fedora/home, want to reduce the size of root and give it for home.
Boot to live boot USB.
Ensure that partitions are not mounted.
Check if partitions are clean
$ sudo e2fsck /dev/fedora/root
$ sudo e2fsck /dev/fedora/home
Reduce file system size in root partition
$ sudo resize2fs /dev/fedora/root <desired size>
# Example
$ sudo resize2fs /dev/fedora/root 30G
Reduce size of logical volume /dev/fedora/root (this must be larger or equal than the file system size)
$ sudo lvreduce -L <desired size> /dev/fedora/root
# Example
$ sudo lvreduce -L 30G /dev/fedora/root
Check /dev/fedora/root again to ensure that it’s ok
$ sudo e2fsck /dev/fedora/root
If root partition is clean, then extend the home partition
$ sudo lvextend -l +100%FREE /dev/fedora/home
Resize home file system
$ sudo e2fsck -f /dev/fedora/home
$ sudo resize2fs /dev/fedora/home
Try mounting root and home to check their size and data. If everything’s ok, reboot.