[dm-devel] Re: Can SCSI commands trigger the reinit of a disabled path?

谢纲 xiegang112 at gmail.com
Wed Jun 10 16:50:26 UTC 2009


On Thu, Jun 11, 2009 at 12:35 AM, <Levy_Jerome at emc.com> wrote:
>> I went through the multipath code and found there was hardware handler
>> for specified hardware, such as emc.  When init path, it will use the
>> trespass command given by the handler. Does this mean it only support
>> the A/PF mode of array? When SCSI commands,  such as SCSI PR, are sent
>> to a disabled path, will trespass be triggered?
>
> In A/PF mode, with failovermode set to 1 (as it should be for dm-mpio)
> the Clariion array will only trespass LUNs on receipt of an explicit
> trespass command, not on other I/O.
Yes, it's what the A/PF mode. But for ALUA, how does device mapper
mutipath driver failback the path and how to avoid Ping-pong state? I
could not find this part of codes.
Thanks,
>
> Jerry Levy, EMC
>
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-- 
Xie Gang




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