Re: RAID6 fails to assemble after unclean shutdown

[Bill Davidsen <davidsen@tmr.com>]

Brian Candler wrote:
> On Wed, Apr 25, 2012 at 09:01:45PM +1000, NeilBrown wrote:
>> Presumably something when wrong during shutdown.  However without more
>> details (--examine) I cannot guess.
>
> OK, thank you.
>
> I've also found
> https://raid.wiki.kernel.org/articles/r/a/i/RAID_Recovery_d376.html
> which shows the --examine option too.
>
> When building the array, would you suggest I also specify --bitmap=internal,
> so that there is less data to resync after an error?

You are being very understated here ;-)
Without a bitmap you can spend days getting back up instead of minutes. Brian 
has the true truth here, unless there is a reason to avoid it, a bitmap is a 
ticket to a sane rebuild.

And if you have a big array, consider putting the bitmap on SSD, faster is better.


-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot