Resize root partition by removing the default /home partition) on CentOS 8

This requires you to be able to ssh into the instance using the root user account and that no services be running as users out of /home on the target machine. You can check this by command fuser /home

The examples are from a default installation with no customation-you NEED to know what you're working with for volumes/partitions to not horribly break things. Use this at your own risk. AT YOUR OWN RISK . Im only tested this on Centos 8 of mine.

By default, CentOS 8 uses XFS for the file system and Logical Volume Manager (LVM), creating 3 partitions: /,/home and /boot. Check with df -h and du -h of /home to make sure the space is enough.

Step 1 - Copy /home Contents

To backup the contents of /home, do the following:

mkdir /newhome
cp -rfp /home/* /newhome

Once that is finished at your back at the prompt, you can proceed to step 2.

Step 2 - Unmount the /home directory

umount -fl /home

Step 3 - Note the size of the home LVM volume

We run the lvs command to display the attributes of the LVM volumes

lvs

Sample output:

  LV   VG Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  home cl -wi-a----- 937.00g
  root cl -wi-ao----  50.00g
  swap cl -wi-ao----   7.81g

Step 4 - Remove the home LVM volume

lvremove /dev/cl/home

Step 5 - Resize the root LVM volume

Based on the output of lvs above, we can safely extend the root LVM by 100% of free space.

lvextend -l +100%FREE /dev/cl/root

Step 6 - Resize the root partition

xfs_growfs /dev/mapper/cl-root

Step 7 - Remove the /home

rmdir /home

Step 8 - rename /newhome to /home directory

mv /newhome /home

Step 9 - Remove the entry from /etc/fstab

Using your preferred text editor, ensure you open /etc/fstab and remove (or put # to comment out) the line for /dev/mapper/cl-home.

Step 10 - Don't miss this!

Run the following command to sync systemd up with the changes.

dracut --regenerate-all --force

orginal from [https://gist.github.com/troyfontaine/87091bd6a5c68f45dd62ced3d12bc377]