[dm-devel] Re: [BUG] dm-mpath and scsi persistent reservation

[Chandra Seetharaman]

Christophe,

The SCSI Hardware handler is created for devices with special needs. It
is available in 2.6.27. One can be written for any device to translate
the scsi sense code to a different error code that the dm understands.
Is this something that coule help this situation ?

Have a look at drivers/scsi/device_handler directory.

Hope this helps,

chandra
On Tue, 2008-10-21 at 23:19 +0200, Christophe Varoqui wrote:
> Hi,
> 
> the dm-mpath multipathing driver enqueues write ios returned by
> the scsi layer with a "reservation conflict" error (on assymetric
> storage controllers, like Clariion, where queue_if_no_path is enabled).
> 
> This is wrong, and a potent data-corrupter : wio sent to a reserved
> scsi device should never be retried on this same device.
> 
> Can someone advise on a viable solution for this problem ? I
> understand the Device Mapper being a block remapper, it is not expected
> to receive scsi errors directly ... but maybe some kind of translation
> might be acceptable. Or is there hope in the request-based remapper ?
> 
> Jens, James, Alasdair, ... as maintainers of the involved subsystems,
> would you care to give some advise on the issue.
> 
> Regards,
> cvaroqui
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