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Re: system crash

 
Doug Phillips
Trusted Contributor

Re: system crash

Willem & Ian:

You've reminded me of a similar situation. The VAX (don't remember what kind, but it wasn't a VAXstation) would just sometimes crash for no reason.

Finally realized that they had a PC as the console, and were using the console to run a data entry application. The Terminal Emulator had F5 mapped to send , and the operator would sometimes accidently hit the F5 key.

I don't remember if there was also a console command that set the break condition, but I moved that operators PC off of the console and put in a dedicated console with break disabled. It never crashed like that again.
Volker Halle
Honored Contributor

Re: system crash

re: console receiving

I'm pretty sure that the system will just HALT and display the console prompt >>>
but it will not crash with a HALT restart bugcheck. The HALT restart crash should only happen, if the console detects, that the operating system has issued a HALT instruction in kernel mode (thus halting the CPU) and the HALT console parameter is set to RESTART. The console would then try to restart OpenVMS via the restart entry point.

Volker.
Doug Phillips
Trusted Contributor

Re: system crash

Thanks, Volker. It was just an old fuzzy memory from the distant past, and I think it did just halt to the >>>. <:-\
Sk Noorul  Hassan
Regular Advisor

Re: system crash

Thanks for the suggestion.

Volker,
I will get back after trying your suggestions.
Richard W Hunt
Valued Contributor

Re: system crash

Too many years and too many versions of O/S ago, a company I worked for tried something like this. It is important to know, at least in overview, how the standby machine learns that it needs to become the duty machine - and how it learns later that it should NOT have tried to become the duty machine.

Can you perhaps give us a brief overview of the method you are using to trigger the change in system status? As I recall, there is a possible situation in which you could run afoul of one of the Goedel theorems on computability that would prevent this from being a truly reliable process, depending on exactly how you approach it.

Sr. Systems Janitor
Volker Halle
Honored Contributor

Re: system crash

Please see my entry from today on the other thread:

http://forums2.itrc.hp.com/service/forums/questionanswer.do?threadId=929654

It may not be possible to obtain the HALT PC from the dump, but ONLY from the halt message on the console.

Volker.
Volker Halle
Honored Contributor

Re: system crash

The data in the CLUE file (read from the crash) is inconsistent:

For a valid restart crash (see [SYS]POWERFAIL routine EXE$RESTART_ATT), the following input values are expected:

AP - Halt reason code (a value between 3 and 31.)
R10 - HALT PC
R11 - HALT PSL

These values do not match in this crash, which makes a hardware problem even more likely.

Volker.