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

Junichi Nomura j-nomura at ce.jp.nec.com
Fri Jul 4 03:10:05 UTC 2014

On 07/03/14 23:34, Bart Van Assche wrote:
> On 07/03/14 16:05, Mike Snitzer wrote:
> 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
>   /dev/dm-0.
> * 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.

Hi Bart,

could you collect output of 'dmsetup table' on the test machine?
My particular interest is whether pg_init is involved or not
since Hannes's patch made major surgery on pg_init processing.

Also, output of the followings while the problem is happening might help:
  dmsetup status
  dmsetup info -c
  cat /proc/diskstat
  multipathd -k"show paths"
  multipathd -k"show maps status"
  multipathd -k"show maps stats"

Jun'ichi Nomura, NEC Corporation

More information about the dm-devel mailing list