On Thursday September 15, hpa@xxxxxxxxx wrote: > 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? mdadm --assemble --update=resync .... should trigger a resync which should recalculate all P and Q (provided your array isn't degraded). This requires shutting the array down of course, but then so would installing the patch. I'm planning a feature whereby you can trigger a resync-like pass which checks all redundancy and either report or reports-and-corrects errors. It's still a little way off though. NeilBrown - 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
