Dear Maintainer, Installing a debian in RAID 1 on two harddrives - /dev/sda and /dev/sdb Using sw raid either during install or (migrating) on the running system. Both the same effect: First I used /dev/md1 on /dev/sda1 and /dev/sdb1 as /boot (ext3) /dev/md5 on /dev/sda5 and /dev/sdb5 as swap (swap) /dev/md6 on /dev/sda6 and /dev/sdb6 as / (ext3) /dev/md7 on /dev/sda7 and /dev/sdb7 as LVM container second, I eased things and dropped /boot - only using /dev/md6 as / (ext3) When unplugging /dev/sda, grub fails to boot. It attemts to wait for /dev/md6 containing root, revealing an UUID that is inappropriate (unplugged /dev/sda). I read about including rootdelay=90 to the grub_cmdline_linux_default option I also tried the option GRUB_DISABLE_LINUX_UUID=true in the /etc/default/grub - same behaviour. I also tried to assure all modules to be available through GRUB_PRELOAD_MODULES="lvm mdraid1x" - just to make sure the raid is up and running. - same behaviour. System fails to boot on the second harddrive, which makes raid1 inefficient. I would expect the grub2 to notice mdraid and adjust UUIDs to boot from both harddrives.