Re: SSA Loops

From: Andreas Schulze (b79xan_at_gmx.de)
Date: 04/28/04 

Date: Wed, 28 Apr 2004 08:48:53 +0200

"Steve Ortiz" <steve@uvg.edu.gt> schrieb im Newsbeitrag
news:573f69ba.0404271204.3b375d4c@posting.google.com...
> "Andreas Schulze" <b79xan@gmx.de> wrote in message
news:<c6ju1g$cuukn$1@ID-208966.news.uni-berlin.de>...
> > "Steve Ortiz" <steve@uvg.edu.gt> schrieb im Newsbeitrag
> > news:573f69ba.0404260717.68b98548@posting.google.com...
> > > Hi,
> > >
> > > I would like to know if anyone has experienced this problem.
> > >
> > > I have a SSA Loop with only one host on it. And it works fine. But
> > > when I add another host to the Loop the transfer rate drops to about a
> > > half.
> > >
> > > Is this the normal behavior? If it is so, where can I find
> > > documentation about it.
> > >
> > > Thanks,
> > >
> > > Steve
> >
> > Hallo Steve,
> >
> > Loop configuration, adapter type and microcode level may be an issue.
Then
> > there are other things that may go wrong such as cables (length,
shielding)
> > and problems resulting from electric power. I would suggest you start
with
> > comparing your installation with the SSA loop configuration rules:
> > http://www.storage.ibm.com/hardsoft/products/ssa/docs/config_rules.html
> > There are quite a lot of combinations of SSA adapters that do not work
> > together in 2-way configuration.
> >
> > HTH,
> > Andreas
>
>
> Thanks Andreas,
>
> I checked the rules, and everything is fine.
> I also checked if the configuration was valid for a 2-way, an it is.
>
> As a matter of fact, every single piece of diagnostic I did tells me
> everything is working fine. And it is, except for that little
> performance problem.
>
> Any other ideas will be greatle appreciated.
>
> Thanks
>
> Steve

Hallo Steve,

just guessing because you said "performance drops to about a half" - is
there a chance that one piece of equipment in your loop is SSA80 while the
rest is SSA160?
Are both adapters using a slot according to the servers corresponding
adapter placement guide?

Regards,
Andreas