Re: Raid10 device hangs during resync and heavy I/O.

[Justin Bronder <jsbronder@gentoo.org>]

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On 16/07/10 14:46 -0400, Justin Bronder wrote:
> I've been able to reproduce this across a number of machines with the same
> hardware configuration.  During a raid10 resync, it's possible to hang the
> device so that any further I/O operations will also block.  This can be
> fairly simply done using dd.  
> 
> Interestingly, this is not reproducible when using a non-partitioned device.
> That is, creating the device with --auto=yes and then directly using it
> functions as expected.  However, using --auto=yes or --auto=mdp and then
> creating a partition across the device will cause the hang.
> 
> From all appearances, this is not just slow I/O, days later the same tasks
> are still blocked.  The rest of the system continues to function normally,
> including other raid devices.
> 
> Below I'm going to include the script I'm using to reproduce, the relevant
> kernel tracebacks, and /proc/mdstat.  Thanks in advance for any help
> resolving this.

My apologies, I should have proof read this first.  I've reproduced using
2.6.28, 2.6.32 and 2.6.34.1.

-- 
Justin Bronder

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