anacanda: should we ignore the bios raid information on a disk when the raid is broken?

[Hans de Goede]

Hi,

On 10/15/2012 10:41 AM, Joshua C. wrote:
> 2012/10/15 Hans de Goede <hdegoede at redhat.com>:
>> Hi,
>>
>>
>> On 10/15/2012 09:23 AM, Joshua C. wrote:
>>>
>>> I have a broken fake raid on my machine (intel p67 chipset with one of
>>> the disks missing) and when trying to install F17 yesterday (with
>>> up-to-date respin done with pungi) I was greeted with the following
>>> message "disk sdXXX has bios raid information and..... blah..... is
>>> part of a broken raid, ignoring sdXXX". After ignoring the message
>>> later on I wasn't given the chance to use the spare disk.
>>>
>>> I thought of patching anaconda to ignore the bios-raid-information and
>>> to allow me to use the disk as I single HDD but I was wondering if
>>> there are any side effects out of this?
>>
>>
>> Yes, the side effect of this is that if we wrongly detect an array as being
>> broken and allow the user to use it, we will destroy the array, nuking any
>> data on it. IOW ignoring this error is simply not an acceptable option.
>>
>> What you can do is remove the bios raid metadata from the disk by going
>> into a rescue shell on the system and run  wipefs on the disk in question
>>
>> Regards,
>>
>> Hans
>
> I don't want to remove the bios data because this is the only way to
> rebild the raid when the next disk arrives. Currently I'm using the
> disk under Linux/Windows without any problems (in AHCI mode). Wipping
> the bios data will remove anything when later I build (re-build) the
> raid with the intel orom...
>
> Can I just install anaything on the second disk and then manually
> adjust the fstab file to automount the disk from the broken raid?

Assuming your raid array is a mirror, and that you won't be partitioning
it or something similar, just adding the existing /home partition to
your fstab yes that should work. Although anaconda will not let you
touch the mirror member during the install, if you've another disk,
putting Fedora 17 on that other disk should work fine, and after
that pointing fstab the disk will work.

BUT *IMPORTANT IMPORTANT IMPORTANT* you MUST remove the entry from
fstab, before rebuilding the array, and then after the rebuild re-add
the entry put now pointing to the raid and not to the single disk,
otherwise Linux will keep using the single disk for your /home !!!

Regards,

Hans