topic Re: MP Console not responding in Operating System - HP-UX

MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 11:08:35 GMT

Hi,

I cannot use the remote console display from the MP. It looks like the session is hung. I believe it is a problem with buffered output being interupted at the console, which is now unresponsive.
I have attempted to recycle the MP, using the XD command but the console is not useable. The MP menu is funtioning fine.

Thanks
Ruan

HP-UX 11.23
rx3600

Re: MP Console not responding

Torsten. — Mon, 14 Jul 2008 11:15:12 GMT

First I would check the setting.

Search the syslog file for an entry like this:

System Console is on the Built-In Serial Interface

Now run a "ps -ef" and look what processes are bound to the console.

Re: MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 11:26:29 GMT

Thanks for the reply Torsten. Unfortunately, the server is in a DMZ and only available access is through the MP console (which is hung and unresponsive). So how can i check the system log? or run a 'ps' command?

Ruan

Re: MP Console not responding

Torsten. — Mon, 14 Jul 2008 11:47:10 GMT

No other way than using a different telnet or ssh session to check if an application is blocking the console.
I don't know your environment, but is there a way to establish another session?

Maybe you can redraw the screen with ctrl l.

Re: MP Console not responding

YAQUB_1 — Mon, 14 Jul 2008 12:05:59 GMT

Hi,

Can U try to physical reset the MP?

I've attached the pdf file; just see the MP VGA (DB-9 pin) upper one of reset button.

BR/
Yaqub

Re: MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 12:45:04 GMT

I dont think i have any other available method of connecting to the host(other than MP console), as it is inside a DMZ. Tried a ctrl+L for a screen redraw but no response.

Yaqub, i will try a manual reset of the MP and let you know how i get on.

Thanks
Ruan

Re: MP Console not responding

YAQUB_1 — Mon, 14 Jul 2008 13:32:09 GMT

Hi,

U just pushes reset the button then after 20 to 30 second latter it will automatically up...

BR/
Yaqub

Re: MP Console not responding

Torsten. — Mon, 14 Jul 2008 13:53:05 GMT

I don't expect any different results since you did a MP reset from the XD command.

If an application blocks the console, a MP reset will not change anything.

Maybe you find something when reading the console log from the MP.

Re: MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 14:10:18 GMT

No, a physical reset did not work. I even unplugged the MP Lan cable.

Looking at the MP console log, I can see that during a display response, a termination signal or interrupt was sent to the console e.g. ctrl+c was pressed. After this the display has not returned.

The console display does not respond to any key strokes. i.e. Tab or return. although i can break out to the MP. screenshot attached.

Re: MP Console not responding

Torsten. — Mon, 14 Jul 2008 14:17:36 GMT

Looks like SAM is running. If you are using VT100, CTRL L should refresh the screen.

You may even try TAB to move around.

If you can't open another session you need to bring down the system anyhow.

Re: MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 14:30:02 GMT

No, tab does not work, no key stroke appears to respond. and yes, i agree that sam looks like it is still running. A clean exit from SAM was not possible as the display became corrupted whilst in use.

Ruan

Re: MP Console not responding

Bill Hassell — Mon, 14 Jul 2008 18:52:28 GMT

This isn't an MP problem so resetting the MP won't help. What has happened is that someone has run a command through the MP and into the console connection to HP-UX. The command is hung -- possibly due to a trashed session, networking problem, etc. It's possible that someone did a telnet to another system (bad idea, especially on the console). You'll have to access the system through another networking option and kill the hung process(es) using the console.

Re: MP Console not responding

Ruan Linehan — Mon, 14 Jul 2008 20:43:46 GMT

Bill, many thanks for the reply.
After seeing your response, I returned to the console and tried a different approach. I entered a ctrl+z and 'backgrounded' the hung process. it worked! I was then returned to a useable command prompt from the console! success.

Now from the console, there are 5 processes running.
1-sh, 2-sam, 3-ps, 4-samx, 5-.

Would I be correct in saying that it was the 'sam/sam gui' process(es) that was giving the console the hung appearance. i.e. the console was fine, the sam app was not.

Also, Is it safe to terminate the two sam related processes and the zombie () process?

Ruan

Re: MP Console not responding

Bill Hassell — Mon, 14 Jul 2008 22:12:17 GMT

> After seeing your response, I returned to the console and tried a different approach. I entered a ctrl+z and 'backgrounded' the hung process. it worked! I was then returned to a useable command prompt from the console! success.

Great idea.

> Now from the console, there are 5 processes running.
1-sh, 2-sam, 3-ps, 4-samx, 5-.

Yuk...samx is running. Someone made some big mistakes trying run a GUI on the console.

> Would I be correct in saying that it was the 'sam/sam gui' process(es) that was giving the console the hung appearance. i.e. the console was fine, the sam app was not.

Very likely. The console is too critical a resource to ever run a background process. I ALWAYS make sure that the DISPLAY variable is never set when logging onto the console. It also makes sam run much faster at the start.

> Also, Is it safe to terminate the two sam related processes and the zombie () process?

Yep. Most likely they are all related. The console should be viewed like all Unix consoles: a command line interface with a dumb terminal.

Re: MP Console not responding

Torsten. — Tue, 15 Jul 2008 04:40:42 GMT

To prevent this behaviour I like to use screens or TSM.

Re: MP Console not responding

Ruan Linehan — Tue, 15 Jul 2008 20:45:14 GMT

I was able to safely terminate the SAM and defunct processes. Console is now back and fully functional.

Thanks to Torsten and Bill for the help!