[Simh] Cluster communications errors

[Mark Pizzolato]

Hi Hunter,

Maybe Dave has something, but maybe not.

I just booted a diskless simh VAX instance from a simh VAX system running on the same LAN.

The Second phase of the boot (after the MOP load of the Secondary boot loader) had a few retries until the boot succeeded and then the node came up and stayed up without issue.  The booting system had this minimal configuration:

      sim> set cpu 256
      sim> set XQ mac=08-00-2b-11-22-44
      sim> attach XQ eth2
      sim> BOOT

       Then entered BOOT XQ at the >>> prompt.

The simh host system in this case was running Windows.  Just for grins, I tried the same thing from a Ubuntu 18.04 Linux system running in a VirtualBox VM on that same Windows host.

The simh Ethernet layer has dramatically more internal packet buffering (maybe 50 X) than anything real DEC hardware ever had.  This might account for the relatively smooth behavior I’m seeing.
Meanwhile, from what you’ve mentioned it seems you’ve got a simh instance talking to real DEC hardware.

Using the 4.0 Current codebase, you might want to look at: HELP XQ CONFIG SET THROTTLE

You may also want to show us the simh VAX configuration file you are using…


-          Mark

From: Simh [mailto:simh-bounces at trailing-edge.com] On Behalf Of Dave Wade
Sent: Wednesday, July 18, 2018 10:14 AM
To: 'Hunter Goatley' <goathunter at goatley.com>; 'Simh' <simh at trailing-edge.com>
Subject: Re: [Simh] Cluster communications errors

Hunter,
Is it set to Autosense Speed and Duplex? Is it getting confused? Can it be set to a fixed speed.
Dave

From: Simh <simh-bounces at trailing-edge.com<mailto:simh-bounces at trailing-edge.com>> On Behalf Of Hunter Goatley
Sent: 18 July 2018 16:58
To: Simh <simh at trailing-edge.com<mailto:simh at trailing-edge.com>>
Subject: Re: [Simh] Cluster communications errors

My mistake. I'm not running V4.0, I'm running V3.10-0 RC1.

After posting, it dawned on me that I should have tried SIMH V3.9.0, but it fails to boot:

(BOOT/R5:0 DUA0







  2..

-DUA0

  1..0..



HALT instruction, PC: 00004C02 (HALT)

sim>
I'm not sure why. I'm using the KA655x.bin that came with V3.9.0 and a new nvram.bin file, but everything else is the same as the V3.10-0 RC1 instance.

I just downloaded the current GitHub sources and compiled them (15fd71b<https://github.com/simh/simh/commit/15fd71b97c8aaec29dc1bbbd3473c3f0d582c9ff>). It boots, but I see the same behavior of losing connection to the cluster.

I also should have mentioned that this dedicated Ethernet card is plugged into the same switch as all of the other cluster members, so that shouldn't be an issue.

Thanks.

Hunter


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20180718/3d356da0/attachment-0001.html>