From mboxrd@z Thu Jan  1 00:00:00 1970
From: hpa@zytor.com (H. Peter Anvin)
Subject: RAID6 on PowerPC is faulty
Date: Thu, 15 Sep 2005 04:31:54 +0000 (UTC)
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If you have been running RAID6 on a PowerPC with Altivec, your RAID is
not two-disk redundant, due to bad Q syndrome computation.

It *is* one-disk redundant, however.

The following patch will fix it:

http://www.kernel.org/pub/linux/kernel/people/hpa/raid6-altivec-fix.patch

.. however, it will not correct an existing array without rewriting
every stripe.

Neil, is there any way to force md to recompute all the syndromes?

	-hpa