How to shrink /home and add more space on CentOS7

Solution 1:

As others have pointed out, XFS filesystem cannot be shrunk.

So your best bet is to backup /home, remove and recreate its volume in a smaller size and give the rest to your /root volume just as Koen van der Rijt outlined in his post.

• backup the contents of /home

tar -czvf /root/home.tgz -C /home .

• test the backup

tar -tvf /root/home.tgz

• unmount home

umount /dev/mapper/centos-home

• remove the home logical volume

lvremove /dev/mapper/centos-home

• recreate a new 400GB logical volume for /home, format and mount it

lvcreate -L 400GB -n home centos
mkfs.xfs /dev/centos/home
mount /dev/mapper/centos-home

• extend your /root volume with ALL of the remaining space and resize (-r) the file system while doing so

lvextend -r -l +100%FREE /dev/mapper/centos-root

• restore your backup

tar -xzvf /root/home.tgz -C /home

• check /etc/fstab for any mapping of /home volume. IF it is using UUID you should update the UUID portion. (Since we created a new volume, UUID has changed)

That's it.

Hope this helps.

Kindly add this to sync the changes:

dracut --regenerate-all --force

Solution 2:

An addition to Ari's answer as I was unable to ssh using public key authentication after following his instructions.

With selinux enabled you may get this message in /var/log/messages (with debug enabled in sshd_config) because /home was recreated:

SELinux is preventing /usr/sbin/sshd from read access on the file authorized_keys

Fix it by:

restorecon -R -v /home

Solution 3:

You can't shrink an XFS filesystem.
You can only grow them with xfs_growfs.

See: https://access.redhat.com/solutions/540013
and
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/xfsgrow.html

It is currently not possible to reduce the size of a partition or logical volume with the xfs filesystem. As a possible workaround in some environments, thin provisioned LVM volumes can be considered as an additional layer below the XFS filesystem.

Find out what's taking so much space under / and split it out as its own filesystem.