It seems to me the device handler infrastructure proposes to translate scsi error codes from requests generated by the device handler itself. I don't know how we can detect a reservation conflict from a device handler without submitting a dangerous write io. I don't see how we could use a device handler to translate an scsi error code from a write io submitted to the multipath device map. Do you ? Regards, cvaroqui > > 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. > > > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
