I’ve installed the urbackup client on a host, and chose “Device-Mapper” snapshots.
The installation routine successfully updated the initramdisk and grub, and whatever else it needs to update, and after a reboot, the root is /dev/mapper/root-98d1f8b1f435 .
So booting works and also snapshots work.
But now there was a kerne update coming in which doesn’t install successfully since updating grub doesn’t work.
The internal command which doesn’t work is:
grub-probe /
grub-probe: error: failed to get canonical path of `/dev/mapper/root-98d1f8b1f435'.
On other hosts it works. The only difference I can see to other hosts is where it properly works, efi boot is used, while on this host legacy boot is used and also /boot is on the root partition.
So where it works:
- grub-efi-amd64 installed
- bios boot and efi boot partitions available
Where it doesn’t work:
- grub-pc installed
- /boot directory is on root partition
At least that’s the only difference I can see.