[openib-general] IBDM and IBMgtSim Proposal Comments

[Hal Rosenstock]

Hi Eitan,

It appears that all the proposed Mellanox diagnostics work on top of the
"OSM" vendor layer. ["OSM" is in quotes as this layer may have started
out as the OSM vendor specific layer but is used by more than just the
OSM (diagnostics and an implementation of a user space SA client).] 

Where does that leave the OpenIB diagnostics and other applications
which do not use this layer ? Does the simulator support these
applications ?

In the OpenIB architecture, umad is the lowest layer library and the
diagnostics are built on that. The OSM vendor layer is built on top of
this. So when the umad and mad libraries are ported to Windows,
everything on top of this will work. This includes all diagnostics
(OpenIB ones as well as the additional tools you are proposing to add).

Also, it appears that the Mellanox simulator is builtin to each
simulated process and so each instance is separate which limits its
usability.

In the Voltaire architecture proposed to be moved forward to OpenIB, the
simulator is standalone and hence is useable by all applications in the
network which can be on different nodes (TCP connections): OpenSM (as
many as you want in the subnet), diagnostics, SA clients, etc. Also, the
Voltaire simulator architecture can use an input file recorded from a
real IB fabric where it appears that this would be manual in the
Mellanox scheme.

The file formats (netlist and topology) are for further study. There are
some good ideas in these file formats which would be incorporated into
the ibnetdiscover format.

-- Hal