Can Windows 2008 handle the maximum number of targets?

I inherited a storport driver and need to increase the number of targets that
it can manage. The fields (pathID, targetID) in an SRB seem to allow a
maximum of 64K devices. However the source code I have access to indicates
that there were problems found when maximumTargetsAllowed was set to 0xFF in
the PORT_CONFIGURATION_INFORMATION.

I verified this myself by changing the code in my driver so that 32 buses
with 255 targets were allowed. The system will now hang somewhere in the boot
process after my driver is initialized and HWFindAdapter is called.

Since Windows should support complex FC fabric topologies with huge numbers
of devices, I find this rather surprising. I suppose it is possible that
there is an error somewhere in my code but I thought I would check here as
well since my changes were so small and the change in behavior so interesting.

see storport.h:
SCSI_MAXIMUM_BUSES 8
SCSI_MAXIMUM_TARGETS_PER_BUS 128


Anyway, even with these limitations number of LUNs is pretty much
unmanageable... What's the point in having that many?

"RamenWarrior" <> wrote in message
news:89C405B6-6B9D-41A1-A8C3-...
>I inherited a storport driver and need to increase the number of targets
>that
> it can manage. The fields (pathID, targetID) in an SRB seem to allow a
> maximum of 64K devices. However the source code I have access to indicates
> that there were problems found when maximumTargetsAllowed was set to 0xFF
> in
> the PORT_CONFIGURATION_INFORMATION.
>
> I verified this myself by changing the code in my driver so that 32 buses
> with 255 targets were allowed. The system will now hang somewhere in the
> boot
> process after my driver is initialized and HWFindAdapter is called.
>
> Since Windows should support complex FC fabric topologies with huge
> numbers
> of devices, I find this rather surprising. I suppose it is possible that
> there is an error somewhere in my code but I thought I would check here
> as
> well since my changes were so small and the change in behavior so
> interesting.

I guess it would have been helpful to see an assertion check fail if the
maximum value was exceeded. The hang was just mysterious.


"Alexander Grigoriev" wrote:

> see storport.h:
> SCSI_MAXIMUM_BUSES 8
> SCSI_MAXIMUM_TARGETS_PER_BUS 128
>
>
> Anyway, even with these limitations number of LUNs is pretty much
> unmanageable... What's the point in having that many?
>
> "RamenWarrior" <> wrote in message
> news:89C405B6-6B9D-41A1-A8C3-...
> >I inherited a storport driver and need to increase the number of targets
> >that
> > it can manage. The fields (pathID, targetID) in an SRB seem to allow a
> > maximum of 64K devices. However the source code I have access to indicates
> > that there were problems found when maximumTargetsAllowed was set to 0xFF
> > in
> > the PORT_CONFIGURATION_INFORMATION.
> >
> > I verified this myself by changing the code in my driver so that 32 buses
> > with 255 targets were allowed. The system will now hang somewhere in the
> > boot
> > process after my driver is initialized and HWFindAdapter is called.
> >
> > Since Windows should support complex FC fabric topologies with huge
> > numbers
> > of devices, I find this rather surprising. I suppose it is possible that
> > there is an error somewhere in my code but I thought I would check here
> > as
> > well since my changes were so small and the change in behavior so
> > interesting.
>
>
>