What are the known supported (and unsupported) features for the GRUB2 lvm module in Debian 9? E.g. does it support the current metadata format "lvm2"?
Is there some extra command or configuration required to access LVM logical volumes from GRUB, even after loading the GRUB
GRUB appears to support MD-raid, but what about when LVM is running on top of MD-raid, does it affect the above questions somehow? Is
grub2-mkconfig expected to support
/boot on MD+LVM?
I need to migrate files from one existing disk into the RAID, so I'm not using the installer to set things up. This is for Debian Stretch. The general idea is
- copy your existing system to a degraded RAID on the new disk
- boot the RAID system
- very carefully double-check and then have the RAID swallow the old disk.
I'm aware this isn't necessarily the most sensible of ideas.
I'm looking at booting from LVM on MD-raid. I won't bother faffing with /boot as a separate MD-raid partition, if I don't need to. It looked like this is what the Debian installer was being used to do in https://wiki.debian.org/DebianInstaller/SoftwareRaidRoot
I created an LV on top of MD-raid, and copied the root filesystem to it. But unlike the pure MD-raid setup described on the RAID wiki,
grub-mkconfig did not find the new Linux instance.
I booted to the GRUB prompt of the original Linux instance, to see what it could do. I can load the
lvm modules. There is no
lvm2 module. This successfully found devices for my GPT partitions, and the MD device
(md/linux) I had created. But it did not find any of the LVM devices I had created, which should have looked like
probe command does not work at all on either
(md/linux); it just says
error: unknown filesystem. So it's not capable of identifying the MD-raid, let alone the LVM stuff, even though GRUB is already accessing the MD-raid.