[dm-devel] v3.15 dm-mpath regression: cable pull test causes I/O hang

Bart Van Assche bvanassche at acm.org
Thu Jul 3 14:34:09 UTC 2014

On 07/03/14 16:05, Mike Snitzer wrote:
> How easy would it be to replicate your testbed?  Is it uniquely FIO hw
> dependent?  How are you simulating the cable pull tests?
> I'd love to setup a testbed that would enable me to chase this more
> interactively rather than punting to you for testing.

Hello Mike,

The only nonstandard hardware that is required to run my test is a pair
of InfiniBand HCA's and an IB cable to connect these back-to-back. The
test I ran is as follows:
* Let an SRP initiator log in to an SRP target system.
* Start multipathd and srpd.
* Start a fio data integrity test on the initiator system on top of
* From the target system simulate a cable pull by disabling IB traffic
  via the ibportstate command.
* After a random delay, unload and reload SCST and the IB stack. This
  makes the IB ports operational again.
* After a random delay, repeat the previous two steps.

If you want I can send you the scripts I use to run this test and also
the instructions that are necessary to build and install the SCST SRP
target driver.


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