[CentOS] Re: Raid5 issues

[Feizhou]

>> It won't boot at all without a raid array setup? That sounds really 
>> funny.
>>
> Actually I'm not 100% sure on this, but I think this is the case.  I 
> believe the first time I set it up as a raid10, assuming that linux will 
> just ignore it.  I installed centos by putting boot on a raid1, and root 
> on LVM over 2 raid1 sets.  I had trouble getting it to boot.

I believe your problem is that fact that there is a raid array 
configured in the bios.

>>> 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.
> Yes, I know this is fakeraid, aka softraid, but I was hoping that using 
> the drivers would make it easier to support raid 10 then with mdadm, 
> which seems to be impossible to get to work with the installer.  I'm not 
> even sure why the raid10 personality is not loaded, as it seems to have 
> been part of the mdadm since version 1.7.

I don't know about a raid10 personality but on boxes I used to run, I 
had raid1 and raid0 personalities loaded...

>>> 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.
>> _________________________________
> I'm trying to install centos 5 - the latest.  How would I go about using 
> dmraid and/or libata?  The installer picks up the drives as individual 
> drives.  There is a drive on the silicon image website, but it's for 
> RHEL4, and I couldn't get it to work.  I'm open to using md for raid, or 
> even LVM, if it supports it.  I just want to be able to use raid10, as I 
> can't trust raid5 anymore.

There you go. The installer picks up the drives individually so the 
installation process treats them as such but the raid bios does not and 
so leads to booting problems. Just blow the raid array configured in the 
  si311x bios the thing should be able to boot. Check also your 
motherboard bios settings too.