Re: Linux mdadm superblock question.

[Rudy Zijlstra <rudy@grumpydevil.homelinux.org>]

H. Peter Anvin wrote:
> On 02/15/2010 07:18 PM, david@lang.hm wrote:
>> On Mon, 15 Feb 2010, H. Peter Anvin wrote:
>>
>>> On 02/15/2010 04:27 PM, Neil Brown wrote:
>>>
>>> There are three options:
>>>
>>> a) either don't boot from it (separate /boot);
>>> b) use a bootloader which installs in the MBR and
>>> hopefully-unpartitioned disk areas (e.g. Grub);
>>> c) use a nonstandard custom MBR.
>>>
>>> Neither (b) or (c), of course, allow for chainloading from another OS
>>> install and thus are bad for interoperability.
>>
>> I have had no problems with XFS partitions and lilo as the bootloader.
>> I've been doing this for a couple of years now without realizing that
>> there is supposed to be a problem.
>>
>
> LILO also can be stuffed in the MBR (and then uses block-pointers from 
> there).  There is one more option that I didn't mention, which is to 
> put the bootloader of a separate partition, OS/2 style.  Again, breaks 
> the standard chainloading model.
There is another configuration that fails. Use partitioned md. I do not 
think it matters whether over whole device or with a partition table. 
Neither grub nor lilo will boot off from it. I've tested that exensively 
with a partition on the disks.  I am using PXE boot to boot 2 servers 
with that configuration. That adds a dependency on the pxe boot server, 
but considering the function of those servers they are moot if that pxe 
server is dead anyways....

Cheers,


Rudy