unable to get pty

[Ahmed Zaher]

Dear All,

I connect to HP-UX server version 11.11 using XDMCP (Xmanager) and I got a terminal warning "unable to get pty" that prevent the prompt to be appeared and I can't run any command.

This case is recovered if I reboot the server and appears again after a few days.
This restart is not acceptable as the server in operation.

Please help.

[Steven E. Protter · Accepted solution]

Shalom,

insf -e

You may need to increase the number of terminal sessions available. The default is 60. nstrel in the kernel

SEP

[Ahmed Zaher]

Hello Steven,

Kindly tell me what should I do in details as I am new in Unix.

Your reply is highly appreciated.

Thanks in advance.

[Jeeshan]

i think it's "nstrtel"

[Dennis Handly]

>This restart is not acceptable as the server in operation.

I assume restarting once to fix the kernel config is acceptable?

>ahsan: I think it's "nstrtel"

Yes. Though npty(5) and nstrpty(5) may also need to be increased.

>tell me what should I do in details

You need to go into SAM and go into the kernel configuration changes menu and change the above 3 variables to 120 or 200. (If they are currently 60.)

[Ahmed Zaher]

Dear All,

Thanks for your interest.

Whatever its nstrel or nstrtel, I don't know what I should do with it as I told you before I am new in Unix.

Please help me with more details.

[Ahmed Zaher]

Dear Dennis,

Thanks for your response.

How I go into SAM and also the kernel menu?

And how to change these values?

Please be patient as this is my first step in unix and face this problem.

Thanks in advance.

[johnsonpk]

1)login to server as root
2)type sam on prompt
#sam
3)terminal version sam window ill open
press enter to get in
4)select kernel configuration
and then select configurable parameters
4)select the kernel parameters by pressing space bar (one at a time)
5)after selecting each parameters that need to change (press TAB and select actions) then select modify tunable parameter and give required value

repeat this step for all three parameters and finally on action menu select the option process new kernel ...

it will ask you the confirmation for reboot



once you did this ur system will reboot with new kernel

Thanks !!
Johnson

[Ahmed Zaher]

Dear johnsonpk ,

Thank you very very very much.

The reason of this problem that many people connect through XDMCP sessions to an application on the server but they incorrectly close the session so the sessions are still opened.

I set the 3 parameters to 120 so I expect that the problem return after a longer period.

Then I want to know a way to kill these sessions without the need to make reboot.


Again many thanks to you.

[Dennis Handly]

>Then I want to know a way to kill these sessions without the need to make reboot.

Do you have an example of a left-over session?
You might be able to use "who -u". For users with a very long time since active "activity" field, you can attempt to kill the process tree.
# UNIX95= ps -Hfu user-name

This will list all of the process trees for "user-name".

You might want to provide the "who -u" output along with the ps(1) output so we can verify what to do next. Please attach a .txt file. (I'm not sure the "retain format" box will work good enough.)