topic Re: Process states requiring a reboot in Operating System - OpenVMS

Process states requiring a reboot

Wim Van den Wyngaert — Mon, 12 Jan 2004 02:19:33 GMT

We have VMS 7.3 with Sybase servers running on it. If Sybase server quotas are too low, the server goes into RWAST and a reboot is needed to free the system.

Does anyone knows why VMS can not kill the process when doing stop/id ? I know that you can write a program to do the job but I don't want to do this. In my opnion, a good OS should always be able to kill the process.

Re: Process states requiring a reboot

labadie_1 — Mon, 12 Jan 2004 04:34:31 GMT

You can find various hacks to bump various quotas (bytlm, diolm...)but I think a better idea is to install Amds sor Availablility Manager: it is the supported way to modify "on the fly" any quota

http://h71000.www7.hp.com/openvms/products/availman/index.html

You should monitor the quotas with Amds or Pquota

http://h71000.www7.hp.com/freeware/freeware40/pquota/

I know several sites runnng Sybase with no problem with Vms V 7.3
Of course, they have put correct quotas.

Rwast stands for Resource Wait Asynchronous System Trap

The doc says
Indicates that the process is waiting for a resource whose availability will be signaled by delivery of an asynchronous system trap (AST).

In most instances, either an I/O operation is outstanding (incomplete), or a process quota has been exhausted.

Re: Process states requiring a reboot

Wim Van den Wyngaert — Mon, 12 Jan 2004 04:54:17 GMT

Labadie,

We also run without problems if nothing special happens. The quotas of Sybase servers are however NOT working as documented. E.g. try to configure a server with 500 users with quotas as documented. Then try to open 500 connections. It will not work. You will encounter the bytlm limit.

But the real problem is that VMS doesn't process the stop/id correctly. And yes, I know many tools exists to correct the quota but nothing garantuees that the software will react error free on dynamic changes.

In my opnion VMS should be changed. Stop/id should ALWAYS work.

Re: Process states requiring a reboot

Lokesh_2 — Mon, 12 Jan 2004 05:07:51 GMT

I guess the stop/id works once the outstanding I/O completes for RWAST process. I have faced several situations in which a backup process got stuck due to some tape drive problem..the process went into RWAST state, and then when the stop/id is issued..the process get killed after some hours ( i think, once the outstanding I/O completes, or the tape drive is restarted )

best regards,
Lokesh

Re: Process states requiring a reboot

Jan van den Ende — Mon, 12 Jan 2004 05:08:23 GMT

Wim,

part of your problem probably is the same as what we experienced, being, VMS 7.2.x & 7.3.x needing much bigger quota than 7.1.x and earlier.
Another, much more painfull part, is the memory leak in Sybase (well, at least in the OmniConnect module). We found that by bumping the bytlm quite a lot, we could postpone the RWAST for some weeks, but you WILL run into it. Our current "solution" is to have our nightly backup procedure kill & restart OmniConnect.

If you REALLY need to kill the process, and cannot implement AMDS or Availability Manager, it CAN be done with Delta, but you are guaranteed NO support, and the risk of typo's is entirely yours!! Back in my old ICL (pre-U*X) days, a similar program was more justly called "DYNAMITE", and the commands for it were called "MATCHES".

I have the instructions only on paper, and it is just too much (and error-prone) to retype, but if you REALLY want to have it (AND USE AT YOUR OWN RISK!), than send me an e-mail with your fax number.

Re: Process states requiring a reboot

Antoniov. — Mon, 12 Jan 2004 05:57:26 GMT

Hello,
old question, process RWAST are not killable. HP (formerly DEC) explain in follow page of user guide:
http://h71000.www7.hp.com/wizard/faq/vmsfaq_007.html#index_x_405

Bye
Antoniov

Re: Process states requiring a reboot

labadie_1 — Mon, 12 Jan 2004 06:19:49 GMT

you said
---------
The quotas of Sybase servers are however NOT working as documented. E.g. try to configure a server with 500 users with quotas as documented. Then try to open 500 connections. It will not work. You will encounter the bytlm limit.
----------
I am a bit surprised, as I think Sybase is not supported on current Vms versions.

I would be much surprised if your doc states Vms V7.3

I think your doc is fine for Vms 6.2 or 7.0

Regards

GÃ©rard

Re: Process states requiring a reboot

labadie_1 — Mon, 12 Jan 2004 06:39:00 GMT

A good pointer on that subject is

Resource Waits in the OpenVMS Operating System

http://www.yrl.co.uk/~phil/vms/rwast.html

Re: Process states requiring a reboot

Wim Van den Wyngaert — Mon, 12 Jan 2004 07:09:46 GMT

Labadie,

Good pointer.
But Sybase doesn't document the quotas anymore. So, how do you calculate them correctly ? Testing is all you can do.