[CentOS] Re: Raid5 issues

Fri May 4 04:04:09 UTC 2007
Feizhou <feizhou at graffiti.net>

Ruslan Sivak wrote:
> Feizhou wrote:
>>
>>> I do have a SIL3114 chipset, and I think it's supposed to be 
>>> supported by device mapper.  When I go to rescue mode, I see it 
>>> loading the driver for SIL3112, but nothing appears under /dev/mapper 
>>> except control.  Are there instructions somewhere on getting it to 
>>> use my controller's raid?
>>
>> Your controller only has a bios chip. It has no raid processing 
>> capability at all.
>>
>> You need to use mdadm. anaconda should be able to let you create to 
>> mirrors and then create a third array that stripes those md devices,
>> _______________________________________________
> Anaconda doesn't let me create a stripe raid set on top of a mirror 
> set.  And it doesn't detect it when I do it manually.
> Also the bios chip presents additional issues.  I believe when I don't 
> have a raid array set up, it won't boot at all.  When I have it on 
> raid10, I had trouble booting, and when I have it on concatenation, 
> everything works fine, until a drive is replaced.  At that point, i have 
> to recreate the array, as concatenation is not a fault tolerant set, and 
> at this point I seem to lose all my data.

It won't boot at all without a raid array setup? That sounds really funny.

> Is there a way to get it to use the raid that's part of the bios chip?  

Repeat after me. There is no raid that is part of the bios chip. It is 
just a simple table.

> Something about device mapper?


You need the fake raid driver dmraid if you are going to set up stuff in 
the bios. What version of centos are you trying to install? libata in 
Centos 5 should support this without having to resort to the ide drivers.