How to Move the Boot Partition to Another Storage Disk Partition in CloudLinux March 25, 2025

This article explains how to move the boot partition to another storage disk partition in CloudLinux.

Issue:

• The current /boot partition is too small and needs to be migrated to a larger partition on another disk.
• A larger reserved space is required before the first partition for leapp.

Note: This process applies to CloudLinux 7, CloudLinux 8, and CloudLinux 9 environments.

Solution:
We assume two disks: /dev/sda (existing boot partition) and /dev/sdb (new storage disk). Follow these steps to migrate the /boot partition from /dev/sda to /dev/sdb.

1. Create a New Partition on /dev/sdb
   1. Ensure there is unallocated space at the beginning of /dev/sdb for the GRUB bootloader. If there is no partition table, create one:

      parted /dev/sdb mklabel msdos

      Note: Ensure /dev/sdb has no important data, as this process will erase existing data.

   2. Create the new /boot partition:

      parted /dev/sdb mkpart primary ext4 1MiB 1024MiB

2. Format the New Partition
   Format /dev/sdb1 with the ext4 filesystem:

   mkfs.ext4 /dev/sdb1

3. Copy Boot Files to the New Partition
   Mount /dev/sdb1 and copy the contents of /boot:

   mount /dev/sdb1 /mnt
   rsync -avh /boot/ /mnt/

4. Install GRUB on the New Disk
   Install the GRUB bootloader onto /dev/sdb:

   grub2-install --boot-directory=/mnt /dev/sdb

   This writes the necessary bootloader files into the reserved space created earlier.

5. Update /etc/fstab
   1. Modify /etc/fstab to reflect the new boot partition. Retrieve the UUID of /dev/sdb1:

      blkid /dev/sdb1

   2. Sample output:

      /dev/sdb1: UUID="9143bc94-1047-4bd7-b77d-ba393cbc71aa" TYPE="ext4"

   3. Edit /etc/fstab to include:

      UUID=9143bc94-1047-4bd7-b77d-ba393cbc71aa /boot ext4 defaults 1 1

   4. Verify the changes:

      mount -a

6. Reboot and Change Boot Priority
   1. Restart the system.
   2. Enter BIOS settings and set /dev/sdb as the primary boot disk.
   3. Boot the system and verify that the new partition is mounted:

      df -h

   4. Expected output should display /dev/sdb1 mounted as /boot:

      Filesystem      Size  Used Avail Use% Mounted on
      /dev/sdb1      989M  149M  773M  17% /boot

7. Recreate GRUB Configuration
   1. Before deleting the old /boot files, regenerate the GRUB configuration:

      grub2-mkconfig -o /boot/grub2/grub.cfg

   2. Sample output:

      Generating grub configuration file ...
      Found linux image: /boot/vmlinuz-...
      Found initrd image: /boot/initramfs-...

   3. Done

Your system is now successfully using the new /boot partition. You can safely remove the old boot files if everything is working correctly.