Hi, I tried reporting this grub2 bug to the Ubuntu 12.04 team, but they are saying that our installation is not "Supported" by Ubuntu since their installer does not permit whole-disk arrays to be built. So, I'm going to try reporting the bug to you. Ubuntu 12.04 uses grub version 1.99-21ubuntu3.1.
This problem is 100% reproducible with Linux md RAID metadata 0.9 and 1.0. We are installing a system with FAI (Fully Automatic Installation), and creating a full disk RAID1 array with two devices (/dev/sda and /dev/sdb). This results in a device /dev/md0 which we then label with a GPT label, and partition with parted, which gives us devices of the form /dev/md0p1, /dev/md0p2, etc. Since we are creating the RAID array with metadata 0.9 or 1.0, the metadata ends up at the end of the array, and so the BIOS should have no trouble reading from each disk individually to load the boot-loader, etc. What's more, grub2 supports GPT, and ordinarily has no trouble booting from a GPT labeled disk. At the end of the FAI installation, we install grub2 like this: grub-install /dev/md0 which results in the usual "no errors reported" message that Grub2 prints out. What we expect at this point is for md to automatically sync the grub2 changes to both /dev/sda and /dev/sdb, and for the BIOS to be able to boot from either device. What happens instead is that when the BIOS attempts to boot from either device, it hangs with a cursor blinking at the top-left corner of the screen *indefinitely*. So, it seems like although Grub 2 thinks the installation went fine, it is not actually OK. The interesting thing is that when we install Grub 2 to /dev/sda and /dev/sdb individually, rather than /dev/md0, everything works as intended. I've seen references on the web indicating that installing to the raw devices is the right thing to do, but I could not find any official documentation supporting the claims. If grub is supposed to be installed to /dev/sda and /dev/sdb, then the bug is that it doesn't complain when an attempt is made to install it to /dev/md0. If it should work even when installed to /dev/md0 (with metadata 0.9 and 1.0), then the bug is that it doesn't actually install properly. In case it is relevant, here is a print out of the partition table, even though (as mention previously), Grub 2 does install successfully when the raw devices are specified (/dev/sda, /dev/sdb): # parted /dev/md0 print Model: Linux Software RAID Array (md) Disk /dev/md0: 500GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 17.4kB 8389kB 8372kB grub bios_grub 2 8389kB 21.0GB 21.0GB ext4 root 3 21.0GB 23.1GB 2097MB linux-swap(v1) swap 4 23.1GB 33.6GB 10.5GB ext4 var 5 33.6GB 54.5GB 21.0GB ext4 tmp 6 54.5GB 75.5GB 21.0GB ext4 local 7 75.5GB 500GB 425GB ext4 data Here is a link to the original bug-report on launchpad which contains the same information as what was sent by email. https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1019389 Thank you very much! Iordan -- The conscious mind has only one thread of execution. _______________________________________________ Bug-grub mailing list [email protected] https://lists.gnu.org/mailman/listinfo/bug-grub
