On Sat, 2018-02-03 at 14:43 -0500, Laurence Oberman wrote: > Hello Doug > > I had emailed you earlier about this issue forgetting to copy others. > > All test devices in the scsi_debug driver share the same ram space so > we cannot really have individual devices for testing stuff like md- > raid. > > I bumped into this a few times already and I think it would be useful > to make each device an individual RAM entry so we can create multiple > unique devices. > > Of course this means also now having to maybe start using attributes > for each device do we can selectively choose which devices get the > fault injections. > > I know its adding complexity here but wanted to get input about the > possibility of changing this. > > For a particular fault injection case this morning I had to use 5 > regular drives and 1 scsi-debug drive to inject faults to reproduce > an > md-raid issue. > > I also wanted a different start sector and range and sent an earlier > patch for that. > > So is this something worth considering ? > If so, i will start working on it. > > Regards > Laurence > > > >
I chatted with Doug about this. Seems that many of the use cases for scsi_debug involved creating high count devices for testing etc. so having each with its own ram space could land up chewing a bunch of memory. I am going to drop this idea for now, but the patch I sent for the choice of sector for MEDIUM errors and count is very useful so I hope that one gets accepted. That patch changes nothing if the two new parameters are not set so should be low risk for acceptance. Thanks Laurence
