Hi. On Tue, Mar 23, 2021 at 01:44:23PM +0100, deloptes wrote: > IMO the problem is that if it is not a partition the mdadm can not > assemble as it is looking for a partition,
My mdadm.conf says: # by default (built-in), scan all partitions (/proc/partitions) and all # containers for MD superblocks. alternatively, specify devices to scan, # using wildcards if desired. #DEVICE partitions containers And /proc/partitions always had whole disks, their partitions, lvm volumes and whatever else can be presented as a block device by the kernel. So mdadm is perfectly capable of assembling whole disk arrays, and it does so for me for more than 10 years. > but not sure how grub or whatever handle it when you boot off the > drive. GRUB2 can definitely boot from mdadm's RAID1 as it has an appropriate module for this specific task. Installing GRUB2 on mdadm array made of whole disks is tricky though. UEFI itself, on the other hand - definitely can not, unless you resort to some dirty hacks. After all, UEFI requires so-called "EFI System Partition" aka ESP. Reco