# FreeBSD and "fake RAID" support on Intel ICHxR chips



## hm (Nov 27, 2009)

Hi,

Before migrating my workstation on FreeBSD, I'd like to know the real status of "Intel Matrix RAID" in FreeBSD. I read that it was supported by ataraid and atacontrol, but I can't manage to know if problems mentioned in this wikipedia page are solved or not ?

I really need a good mirroring support, and I couldn't find any piece of information about these specific chips in the hardware notes...

If anyone has a clue... Thanks !


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## knarf (Nov 27, 2009)

I'd recommend not to use ataraid (ar).

Try gmirror(8) or zmirror (zpool(8)) instead.

This way you do not rely on hardware features at all and you can be sure you can move the disks to any other machine without problems.


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## hm (Nov 27, 2009)

Thanks for this suggestion, but, as you guess, it is not possible : the workstation's disks are shared between unix and ms windows, so I must use ataraid, or find another option (Debian probably) if freebsd does not support such chips well.


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## knarf (Nov 27, 2009)

Okay, I understand.

I use ataraid(4) on some machines. It works fine. I never had the problems referenced in the wikipedia, but I had problems with dying disks (so I have a bit experience in recovery). The send-prs are quite old, at least one of them is closed (did you read them all?). And from what I understand the problems are ataraid(4) in general and not specific to your chipset.

So if your disks are okay, it will work fine. If there is a problem with the disks you have to be familiar with the chipset menu and the software in FreeBSD (atacontrol rebuild for example). And if you do not trust FreeBSD here (though I see no reason why you shouldn't), just boot Windows until the problem is solved.

Ah, and if you really want to get rid of ataraid and have to use Windows and another os, you could use the Windows software raid only on the windows slice (sorry, don't know the English terms, dynamic disk?). I think Windows converts to GPT (instead of MBR) then, a good start for using gptzfsboot.


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## knarf (Nov 27, 2009)

I just checked kern/121899 ([2] in http://en.wikipedia.org/wiki/Intel_Matrix_RAID): The status is "open" but the changes from the suggested patch can be found in the 8.0-RELEASE kernel. [committers here?]

[3] is closed.

[4] and [5] address the same problem:

kern/102211: [ar] [patch] detach raid member and reboot will cause panic (ICH7)
kern/108924: [ar] Panics when Intel MatrixRAID RAID1 is degraded

The suggested patch is not in 8.0-RELEASE. So maybe you want to try to reproduce the problem, apply the patch and try to reproduce again. This would help to remove the problematic line out of wikipedia.


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## phoenix (Nov 29, 2009)

The better solution would be to pick up a real hardware RAID controller, that works with both OSes, and handles all the RAID functionality.


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## hm (Nov 30, 2009)

I'll probably give FreeBSD a try when I have a few hours free. I'll be back ;-) !


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