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Date: Thu, 5 Apr 2007 06:52:22 -0500
From: Alexander Anderson <a.anderson@utoronto.ca>
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Subject: Re: Hardware Raid on Intel DG965OT Motherboard
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Thu, Apr 05, 2007 at 08:52:44 AM, Antony Mawer wrote:
>>I have Intel D975XBX2 with two on-board SATA RAID controllers: one is Intel
>>Matrix and the other is Marvell storage. I have FreeBSD 6.2 with RAID-5
>>using Intel Matrix Storage. It seems to work fine.
> 
> You may want to re-think that option... according to the ataraid(4) man 
> page, RAID5 is not functional (ie. you have about as much data safety as 
> a RAID0 stripe set does):
> 
>>CAVEATS
>>     RAID5 is not supported at this time.  Code exists, but it neither uses
>>     nor maintains parity information.

The ataraid driver provides *software* RAID. But doesn't Intel Matrix
Storage gives *hardware* RAID support? How could I tell if software is at
play?

> One drive failure and you will be in for a whole world of hurt...

I was going to do a test and simulate a drive failure (and see how to
rebuild the array). I haven't had a chance to try that yet.