Re: [gentoo-user] Re: [O/T] RAID help - now won't boot

Michael Hampicke <mh@××××.biz> wrote:
>Am 20.10.2013 15:13, schrieb Mick:
>> On Sunday 20 Oct 2013 13:57:34 Michael Hampicke wrote:
>>> Am 20.10.2013 11:54, schrieb Mick:
>>>> Any ideas why the Ubuntu installation won't boot?
>>>
>>> My guess would be, you cannot boot, because if you install grub in
>>> /dev/md0.
>>>
>>> Upon boot the bios cannot find stage1 of the bootloader, which
>normally
>>> lies in the MBR (which also houses the partition table).
>>
>> I see ... so installing the MBR code in the /dev/md0 block device is
>further
>> down the disk than where BIOS is looking for it and that's why it
>errors out?
>>
>
>That would be my guess. Maybe someone more knowledgeable on how mdadm
>writes stuff on the disk can jump in and provide additional info. But
>I'm pretty sure, if you install grub in md0, it's not in that place on
>the disk where the bios is actually looking for.
>
>>
>> It seems to me then that I *have* to create normal partitions on
>/dev/sda &
>> /dev/sdb, or I would need a different boot drive.  Is there another
>way to
>> overcome this problem.
>
>Maybe create two mds. md1 (sda1, sdb1) is a small boot partition which
>contains stage2+, the kernel and the initramfs. And md2 (sda2, sdb2)
>which acts as another block device with partition table, etc...
>In this setup you could install grub in the mbr of sda and sdb
>(grub-install /dev/sda...)
>
>A quick google on this subject returned no usable results. But I am off
>now until tomorrow.

I would suggest trying it by usong the older metadata format.
Check the man pages, but I thinl it would be --metadata=0.90 (or similar) during creation.
That might put the metadata at the end, rather then at the front. (Or it's the other way round and new metadata does it at the end.)

--
Joost
Ps. I have never tried it this way (full disk raid for boot device) using linux software raid.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.