FC4 and Sil 3512 SATA RAID

[Dan]

Christopher J. Bottaro wrote:
> Dan wrote:
>
>   
>> Christopher J. Bottaro wrote:
>>     
>>> Hi,
>>> I have a motherboard that has the Sil 3512 chipset for SATA RAID.  I made
>>> a
>>> RAID-0 set for my hard drives in the BIOS.  I installed FC5 from DVD and
>>> it
>>> recognized the RAID set as a single hard drive...perfect!  The problem is
>>> that FC5 is too new for me and some stuff doesn't work.  I want to
>>> downgrade to FC4.  Is there any way to get the FC4 installer to recognize
>>> my RAID set as a single hard drive like the FC5 installer does?
>>>
>>> Thanks for the help.
>>>
>>> P.S.  I know "hdparm -t" is a crappy test, but FC5 using the Sil 3512 for
>>> RAID got 85 MB/s, where as FC4 using the same hard drives and 100%
>>> software RAID got 50 MB/s.
>>>
>>>   
>>>       
>> Well...it's possible, but not advisable. I did it with FC4; take a look
>> at http://www.fedorasolved.com/viewtopic.php?t=154 . Note this requires
>> an alternate/external hard drive to install onto at first, and fairly
>> good knowledge of partitioning and fedora/GRUB's labeling schemes.
>> -Dan
>>
>>     
>
> Oh dang.  I read a post that that link referenced
> (http://www.spinics.net/lists/ataraid/msg02310.html).  I followed
> everything up until after the grub part.  I don't understand what mkinitrd
> is (or is for) and why it needs to be patched.
>
> Oh well, I'll just deal with FC5's newness for now.  :)  Thanks.
>
> -- C
>
>   
Heh, probably should read up on that if you want to do this. mkinitrd 
makes the initramdisk, which is what Fedora starts up from after GRUB 
boots it. The initrd normally is not made with dmraid support, so 
mkinitrd is patched to give it that; then, you need to make a new initrd 
image with the patched mkinitrd, and that initrd will have dmraid. :)
-Dan