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 - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html