Dear Maintainer, Grub has been working flawlessly on all 50 or so Debian systems that I maintain. I have been running grub-install manually after kernel updates to ensure all disks in the RAID array have a bootable disk. Yesterday and today I upgraded grub with apt-get upgrade to apply the latest security patches for Wheezy in the grub-pc_1.99-27+deb7u3_amd64.deb package. This was the result: Setting up grub-pc (1.99-27+deb7u3) ... Configuring grub-pc ------------------- The GRUB boot loader was previously installed to a disk that is no longer present, or whose unique identifier has changed for some reason. It is important to make sure that the installed GRUB core image stays in sync with GRUB modules and grub.cfg. Please check again to make sure that GRUB is written to the appropriate boot devices. If you're unsure which drive is designated as boot drive by your BIOS, it is often a good idea to install GRUB to all of them. Note: it is possible to install GRUB to partition boot records as well, and some appropriate partitions are offered here. However, this forces GRUB to use the blocklist mechanism, which makes it less reliable, and therefore is not recommended. 1. /dev/sda (500107 MB; WDC_WD5003ABYX-01WERA1) 4. /dev/sdd (500107 MB; WDC_WD5003ABYX-01WERA1) 2. /dev/sdb (500107 MB; WDC_WD5003ABYX-01WERA1) 5. /dev/dm-0 (9999 MB; ccs5a-root) 3. /dev/sdc (500107 MB; WDC_WD5003ABYX-01WERA1) (Enter the items you want to select, separated by spaces.) GRUB install devices: 1 2 /usr/sbin/grub-probe: error: no such disk. Auto-detection of a filesystem of /dev/mapper/ccs5a-root failed. Try with --recheck. If the problem persists please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <bug-grub@gnu.org> /usr/sbin/grub-probe: error: no such disk. Auto-detection of a filesystem of /dev/mapper/ccs5a-root failed. Try with --recheck. If the problem persists please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <bug-grub@gnu.org> GRUB failed to install to the following devices: /dev/sda /dev/sdb Manually running grub-install also fails: lfcjf@ccs5:~$ sudo grub-install --no-floppy /dev/sda /usr/sbin/grub-probe: error: no such disk. Auto-detection of a filesystem of /dev/mapper/ccs5a-root failed. Try with --recheck. If the problem persists please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <bug-grub@gnu.org> It seems grub-probe is getting confused by / on LVM. As I said, there have been countless kernel upgrades where the previous version of grub worked flawlessly. The other system that failed was a kvm VM. If I have time next week, I'll send a followup report on it. But it is not a production system and so I'm not spending time on it today. So far, I have not figured out a workaround. If I do, I'll followup.