Resize root partition on an AlmaLinux OS

Resizing Root Partition on AlmaLinux 10 (LVM + XFS)

Since XFS filesystems cannot be shrunk, increasing the root partition requires backing up the /home partition, deleting it, expanding /root, and then recreating /home.

Prerequisites

  • A backup location with enough space (e.g., /mnt/w).
  • Root or sudo access.

Step 1: Backup Home Data

Backup all data from /home to a temporary location.

sudo mkdir -p /mnt/w/home_backup
sudo rsync -aHAX --progress /home/ /mnt/w/home_backup/

Step 2: Unmount and Remove the Home Volume

Ensure no processes are using /home, then unmount it and remove the Logical Volume (LV).

sudo fuser -mk /home
sudo umount /home
sudo lvremove /dev/almalinux/home

Step 3: Extend the Root Volume

Extend the root LV by the desired amount (e.g., 100GB) and grow the XFS filesystem.

sudo lvextend -L +100G /dev/almalinux/root
sudo xfs_growfs /

Step 4: Recreate the Home Volume

Create a new LV using the remaining free space and format it with XFS.

sudo lvcreate -l 100%FREE -n home almalinux
sudo mkfs.xfs /dev/almalinux/home

Step 5: Update /etc/fstab

The new volume has a different UUID. You must update /etc/fstab to prevent boot/mount failures.

  1. Get the new UUID: 
    lsblk -f /dev/almalinux/home
  2. Edit /etc/fstab: 
    sudo vi /etc/fstab
  3. Replace the old UUID for /home with the new one, or use the device path: /dev/mapper/almalinux-home /home xfs defaults 0 0

Step 6: Mount and Restore Data

Mount the new partition and restore your files.

sudo mount -a
sudo rsync -aHAX --progress /mnt/w/home_backup/ /home/