Re: raid6 rebuild

On 4/5/07, Lennert Buytenhek [off-list ref] wrote:

On Thu, Apr 05, 2007 at 09:54:14AM -0400, Bill Davidsen wrote:

quoted

I confess, I would feel safer with my data if the rebuild started
over, I would like to be sure that when it (finally) finishes the
data are valid.

With disk #3 about to die, I'd have felt safer if it first finished
rebuilding the replacement disk for failed disk #1 (that rebuild had
almost completed at that point), safeguarding the array against a
third disk failure.

I agree, the current arrangement seems to throw away a significant
amount of work.  Yes, you will need to resync when re-adding the
second disk, but in the meantime might as well try to get a redundant
mode at all costs.

Yeah, I know, you're not supposed to lose three disks within one day.

quoted

If you replaced the 2nd drive, then a full rebuild would be required
in any case, to get ALL drives valid.

You could finish the last little bit of the resync of the replacement
for failed disk #1 (by looking at P+Q), and then re-sync the replacement
for failed disk #2 (by looking only at P..)
-

--
Dan