Re: [PATCH v2 0/2] Update SCSI target removal path

["Ewan D. Milne" <emilne@redhat.com>]

On Wed, 2016-03-30 at 13:01 +0200, jthumshirn wrote:
> [+Cc linux-scsi back]
> On 2016-03-30 02:59, Martin K. Petersen wrote:
> >>>>>> "Ewan" == Ewan D Milne <emilne@redhat.com> writes:
> > 
> > Ewan> I would probably use an APCON or other physical layer switch to
> > Ewan> drop the FC link and test the error recovery/device loss.  But we
> > Ewan> don't have one.
> > 
> > They go for a couple of hundred bucks on eBay. I had one of these in a
> > previous life and it was awesome.
> 
> Though this would work (like any other FC/FCoE switch) I thought more of 
> a simulated environment. scsi_debug, Qemu, something like that.

You might be able to do something with that but it doesn't quite do the
same thing in terms of how a HBA/driver will react to a fault.  You also
need to be sure there is enough entropy in the timing of when the target
goes away.  (Otherwise, you could just rmmod scsi_debug...)

> 
> I've had a look at scsi_debug but it seems like it's quite some 
> refactoring needed to get it to a point where one can simulate target 
> errors. I kinda like the idea of having something in 
> tools/testing/selftest but it'll probably end up with a FC switch.
> 
> Johannes