[OpenIndiana-discuss] CIFS performance issues

[James Carlson]

Robin Axelsson wrote:
> On 2012-01-27 15:32, James Carlson wrote:
>> What NWAM is supposed to do is configure only one usable interface
>> (guided by user selection criteria) for the system.  The fact that you
>> got multiple interfaces configured is indeed an anomaly, and one I can't
>> explain.  I don't know how you got there in the first place.  It
>> shouldn't have happened.
> 
> I don't agree with you on that. Many motherboards come with dual
> ethernet ports (i.e. dual NICs, I have counted the chips myself) and it
> is not uncommon with laptops with one wired ethernet interface and a
> wireless one. So as you said, there is the potential risk of
> interference between the two interfaces even though one may not even be
> connected.

Don't agree how?

NWAM's original mission in life was to make sure that only one interface
was configured at a time, regardless of how many might be available.
I'm pretty darned sure that's true, because I was involved in that project.

That's sort of the whole point.  NWAM looks over the available
interfaces, figures out which ones are usable, then applies a set of
policies to determine which one of all of those will be used.  It then
disables the others and properly configures the rest of the system to
use that one chosen interface.  If conditions change, then it
reevaluates the situation.

The canonical example would be a laptop with wired and wireless
interfaces.  The default rule would be to use wired if it's connected
and working, and otherwise use the wireless interface.  Not both at any
one time.

Things changed a bit in the next incarnation of NWAM, and I wasn't as in
touch with that one.  However, the fundamental design goal of producing
a working configuration -- and avoiding known unworkable configurations
-- wasn't abandoned.  So, what you saw was either a bug or a
misconfiguration of some sort, and you'd need to find someone who knows
more about that second NWAM.

>> That sounds backwards to me.  If a buggy driver exists, then the bugs
>> should be fixed, or the driver should be discarded.  There's no reason
>> on Earth to have some other bit of software "warning" users about
>> someone else's software design failures, whether real or otherwise.  At
>> best, that other software would just become a repository of uselessly
>> independent misjudgment -- as new, unknown buggy drivers are written and
>> old ones are repaired.
>>
> 
> True, but what do you do when *all* you've got is a buggy driver that
> _may_ work well on your system? Either you use the driver or you go get
> a network card that is proven to work well with Solaris/OpenIndana. The
> thing is that a substantial part of the development of OI depends on the
> charity of willing developers and their spare time, so you have to make
> the best out of what you have at your disposal.

I think we have differing viewpoints on system architecture.

To me, it would be a very poor design choice to embed detailed knowledge
of some driver writer's parental marital status into an independent part
of the system.

If all compromised drivers exposed a "I'm potentially garbage" flag,
then, fine, that independent part could read that flag and do whatever
it wants based on it.  But merely reading the letters "rge" and deciding
to impugn the connection based on some history or accusations strikes me
as untenable.

-- 
James Carlson         42.703N 71.076W         <carlsonj at workingcode.com>