RE: RAID6 and crashes (reporting back re. --bitmap)

["Graham Mitchell" <gmitch@woodlea.com>]

Thanks to everyone for replying, it is indeed a simple operation and
completes immediately. I was just worried since I equate grow more to an
array reshape than to a management/tune option. I guess it's just my
paranoia showing thru... :)


G

> -----Original Message-----
> From: Roman Mamedov [mailto:roman@rm.pp.ru]
> Sent: Friday, June 11, 2010 12:42 AM
> To: Graham Mitchell
> Cc: linux-raid@vger.kernel.org
> Subject: Re: RAID6 and crashes (reporting back re. --bitmap)
> 
> On Fri, 11 Jun 2010 00:31:57 -0400
> "Graham Mitchell" <gmitch@woodlea.com> wrote:
> 
> > Can you do this on a live array, or can it only be done (as the docs
> > seem to suggest), with the create, build and grow options?
> 
> It is a variant of the grow operation, but it can be done on a live array,
even
> mounted, and completes instantly:
> 
> mdadm --grow /dev/md0 --bitmap=internal --bitmap-chunk=131072
> 
> In my experience, removing the bitmap (setting it to none) may
occasionally
> fail (probably when the array has a lot of outstanding write requests),
but
> just try again when it's a bit quieter, and it'll work.
> 
> --
> With respect,
> Roman