Re: Block Size for Windows

[Kent Overstreet <koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>]

On Wed, Aug 29, 2012 at 06:42:43PM +0100, Jonathan Tripathy wrote:
> On 29/08/2012 18:34, Kent Overstreet wrote:
> >On Wed, Aug 29, 2012 at 06:22:30PM +0100, Jonathan Tripathy wrote:
> >>On 29/08/2012 13:12, Jonathan Tripathy wrote:
> >>>On 29.08.2012 08:03, Kent Overstreet wrote:
> >>>>I just went ahead and backed out the problematic change. Haven't even
> >>>>tried building the code yet - but if you feel lucky, it's up. I bet it
> >>>>fixes it.
> >>>Hi Kent,
> >>>
> >>>I pull down your latest code and did a build. I'm pleased to say
> >>>that Windows has now installed. I will do some further
> >>>testing/benchmarking to make sure that the install is stable.
> >>>
> >>>Many thanks for your quick help
> >>Hi Kent,
> >>
> >>A little bad news. With this new build, the spindles are getting
> >>thrashed and this is constantly (never stopping) spewing out on my
> >>netconsole:
> >>
> >>[23198.979215] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67230714 4
> >>[23198.979304] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67234814 4
> >>[23198.979393] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67235834 4
> >>[23198.979595] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67276796 3
> >>[23198.979696] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67297276 4
> >>[23198.979791] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67248126 4
> >>[23198.979886] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67284987 3
> >>[23198.979966] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67305471 4
> >>[23198.980215] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67329017 4
> >>[23198.980337] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67323899 4
> >>[23198.980542] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67330047 2
> >>[23198.981707] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67335164 3
> >>[23198.982164] md/raid10:md7: make_request bug: can't convert block
> >>across chunks or bigger than 512k 67346429 4
> >>
> >>Any ideas?
> >Oh hell, I see the problem. That one is not going to be such an easy
> >fix. I'm going to have to think about it.
> >
> >Amusing part is it looks like blocksize = 4k was working around the
> >problem... :/
> Ah, ok :)
> 
> Please keep me posted when this is fixed, I'm very keen to see
> bcache deployed in our cloud infrastructure :)
> 
> If there is anything I can do to help from a testing standpoint,
> please let me know.

I had an idea for how to work around it :) (and other potential issues
I recently became aware of).

More untested code up!