Problem with S1 connection from SP2 Control Workstation to S7A

I was recently involved in a Disaster Recovery test for one of our remaining
PSSP clusters. At the DR site I encountered a problem with the S1 serial
connection to an S7A.

There are three nodes: two S7As and one p680.
having recovered the Control Workstation and cleared out its SDR I tried to
add the three servers using the spframe command. For all three, it appeared
to work. However, although the p680 and tone of the S7As were fine and were
subsequently installed the second S7A didn't work correctly.

The SAMI connection was OK so it wasn't simply a matter of having the TTY
ports the wrong way round: I was able to use spmon to power the server off
and on, and I could see the LED codes. However, there was no console output
through s1term. This meant that nodecond failed and I was unable to install
the server.

All of the serial cables etc were changed.

Can anybody suggest what might have caused this problem?

The only issue like this which I've encountered before is where the S7A's
console output has gone to the S2 port, and - iirc - it was necessary to
boot to maintenance mode from that console in order to switch it to another.
I don't believe that was the case this time but I can't be sure as I didn't
set up the system myself and I didn't have access to the hardware. But
remember that the other two - both SAMI protocol - worked fine.

Please note that I don't have access to these servers now, so I am very
limited in the amount of additional information I can provide.

--
Simon Green
Altria ITSC Europe s.a.r.l.

AIX-L Archive at https://new-lists.princeton.edu/listserv/aix-l.html
<https://new-lists.princeton.edu/listserv/aix-l.html>

New to AIX? http://publib-b.boulder.ibm.com/redbooks.nsf/portals/UNIX
<http://publib-b.boulder.ibm.com/redbooks.nsf/portals/UNIX>

N.B. Unsolicited email from vendors will not be appreciated.
Please post all follow-ups to the list.

Relevant Pages