SLES 12: Put /boot on LVM (Workaround for Installer Limitation)

Quick one-liner: The SLES 12 installer won't let you mount /boot on LVM — but it's just an installer limitation. Here's the workaround to get /boot on LVM anyway.

🤔 Why This Matters

GRUB2 can boot from LVM just fine. The SLES 12 installer is what refuses to let you mount a logical volume as /boot. It's not a technical limitation — it's an installer restriction.

If you want all your partitions on LVM (including /boot), here's the workaround.

🔧 Step 1: During Installation — Use /newboot as a Placeholder

In the SLES 12 installer's Expert Partitioner, create your logical volumes as usual — including one for /boot. But instead of mounting it as /boot, mount it as /newboot.

Your layout should look like:

system/boot   →   /newboot   (XFS or ext4)
system/root   →   /          (XFS)
system/swap   →   swap

Proceed with the installation normally.

🔧 Step 2: After Installation — Move /boot to LVM

Once the system boots up, move the contents from the default /boot to your LVM volume:

sudo mv /boot/* /newboot/
sudo umount /newboot

🔧 Step 3: Update /etc/fstab

Edit /etc/fstab and change the /newboot entry to mount at /boot:

/dev/system/boot    /boot    xfs    defaults    0 2

Then mount:

sudo mount -a

Verify:

df -h /boot

You should see /dev/mapper/system-boot mounted at /boot.

🔧 Step 4: Reinstall GRUB and Update Config

sudo grub2-install /dev/sda
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

🔧 Step 5: Reboot and Verify

sudo reboot

After reboot, verify:

df -h /boot
# Should show /dev/mapper/system-boot

cat /boot/grub2/grub.cfg
# Should exist and contain menu entries

✅ Quick Reference

Note: This is specific to SLES 12. On SLES 15, the installer allows /boot on LVM directly. See our SLES 15 LVM guide for the streamlined approach.