Re: GRUB 1.99-21 can't boot from second drive of MD RAID

[Andrey Borzenkov]

В Mon, 16 Jun 2014 01:36:26 +0100
Philip Pemberton <address@hidden> пишет:

> Hi,
> 
> I have an Ubuntu 12.04 Server system set up with a combination of 
> software RAID-1 (md) and LVM:
> 
> $ sudo parted /dev/sda print
> Model: ATA WDC WD20EFRX-68E (scsi)
> Disk /dev/sda: 2000GB
> Sector size (logical/physical): 512B/4096B
> Partition Table: gpt
> 
> Number  Start   End     Size    File system  Name         Flags
>   1      1049kB  2097kB  1049kB               bios_grub_0  bios_grub
>   2      2097kB  1076MB  1074MB               raid_boot_0
>   3      1076MB  2000GB  1999GB               raid_lvm_0
> 
> The other drive is partitioned identically, except the names end "_1".
> 
> "raid_boot" is the /boot partition, an ext2fs RAID-1 created with "md". 
> Ubuntu calls this "md0".
> "raid_lvm" is another md RAID-1 which contains an LVM volume group.
> 
> 
> I've just replaced both disks (one was faulty and the other wasn't far 
> from it), cloned the partitions and installed GRUB. My problem is:
> 
>    - With both disks installed, the system boots fine
>    - With only sda installed (simulating a failure of sdb), the system 
> boots fine
>    - With only sdb installed (simulating a failure of sda), the system 
> boots to the GRUB menu, then tries to boot and reboots the system 
> instead. If I exit the GRUB menu to a GRUB command line, any command 
> (even 'help' or 'ls') causes GRUB to spontaneously reboot the PC without 
> even attempting to boot Linux.
> 

I tested openSUSE 13.1 with grub 2.00 in QEMU and I can boot if I omit
first drive. Do you have any chance to test newer grub versions?

> Curiously, if both drives are installed and I instruct the BIOS to boot 
> from sdb, GRUB works fine.
> 
> I initially installed GRUB using 'grub-install /dev/sda' followed by 
> 'grub-install /dev/sdb'. I've also tried reinstalling GRUB (apt-get 
> purge grub-common; apt-get install grub-pc) but this had no effect.
> 
> Can anyone tell me what I'm doing wrong here? All I want is for my 
> server to boot even if one of the two RAID-1 mirrored drives has failed.
> 
> Thanks,