[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [dm-devel] multipath - AAArgh! How do I turn "features=1 queue_if_no_path" off?

Hannes Reinecke wrote:
malahal us ibm com wrote:
John Hughes [john Calva COM] wrote:
I want to turn queue_if_no_path off and use

               polling_interval        5
               no_path_retry           5

because I've had problems with things hanging when a lun "vanishes" (I deleted it from my external raid box).

But whatever I put in /etc/multipath.conf when I do a "multipath -l" or "multipath-ll" it shows:

Did you reload the mapper table?

360024e80005b3add000001b64ab05c87dm-28 DELL ,MD3000 [size=68G][features=1 queue_if_no_path][hwhandler=1 rdac]
\_ round-robin 0 [prio=3][active]
\_ 3:0:1:13 sdad 65:208 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 4:0:0:13 sdas 66:192 [active][ghost]

Which is entirely correct. The 'queue_if_no_path' flag _has_ to
be set here as we do want to retry failed paths, if only for
a limited amount of retries.

The in-kernel dm-multipath module should handle the situation correctly
and switch off the queue_if_no_path flag (= pass I/O errors upwards)
when the amount of retries is exhausted.
As far as I can tell it retries forever (even with polling_interval 5 and no_path_retry 5). The mdadm raid10 built on top of the multipath devices hangs, even /proc/mdstat hangs.

You're saying that without queue_if_no_path multipath basicly won't work - mdadm will see I/O errors on multipath devices if a path fails?

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]