(UEFI) Booting Xen from a btrfs snapshot fails
This document (000020602) is provided subject to the disclaimer at the end of this document.
SUSE Linux Enterprise Server 12
One can see errors similar to:
# zypper in --allow-downgrade --oldpackage xen-4.14.3_04-3.15.1
First, grub2-mkconfig copies xen-<version>.efi (and other files) into /boot/efi/efi/sles/
/boot/efi is the EFI partition, which is VFAT formatted. On VFAT no BTRFS snapshots are possible, means booting is not possible if Xen should boot from an older snapshot than the current as the xen.efi loader must match the currently installed xen version.
Reason: the Xen image is currently booted via Xen EFI loader
# grep -m1 -A 1 'Loading Xen' /boot/grub2/grub.cfg echo 'Loading Xen 4.14.3_06-150300.3.18 with Linux 5.3.18-150300.59.49-default ...' chainloader /efi/sles/xen-4.14.3_06-150300.3.18.efi xen-4.14.3_06-150300.3.18.efi config.1However, the current snapshot boot implementation is based on passing "rootflags=subvol=/@/.snapshots/<id>/snapshot" kernel boot parameter, and there is no way to make Xen.efi loader use this parameter from GRUB2.
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- Document ID:000020602
- Creation Date: 07-Jun-2022
- Modified Date:07-Jun-2022
- SUSE Linux Enterprise Server
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