topic /dev/pty in Operating System - HP-UX

/dev/pty

joe_91 — Thu, 01 Feb 2007 16:08:49 GMT

i have 2 machines on which my application launches (xwindows) and now suddenly it stopped working(as application increased some users recently) on one while it is fine on another. the kmtune ouput between the two machines match. the xwindoes application launches a remote telnet session (so i guess it does not use this machines'kernel parameters (npty, nstrtel etc) but i find one difference between the two boxes. on the box that works

cd /dev/pty
ll|wc -l
2049

on the box which does not work
cd /dev/pty
ll|wc -l
61

does this matter?
if so, both the machines have the same kernel parameters(so why would have more pty files?).please let me know if this would be an issue?

Thanks

Joe

Re: /dev/pty

A. Clay Stephenson — Thu, 01 Feb 2007 16:19:45 GMT

Because the kernel tunables were increased but insf was not run to increase the number of device nodes. Run insf but note that while this will increase the number of device nodes it may not fix your problem because you may not have found the fundamental cause.

Re: /dev/pty

James R. Ferguson — Thu, 01 Feb 2007 16:21:48 GMT

Hi Joe:

Have a look at Technical Knowledge Base documents:

# KBRC00013957
# KBRC00014047

Regards!

...JRF...

Re: /dev/pty

joe_91 — Thu, 01 Feb 2007 16:34:12 GMT

I now clearly remember. we increased npty to 2048 on both machines from 60 but donr remember running the insf commnds on server2 (where we have the issue). may be that explains the lesser ptys under /dev/pty.. i will try to increase this and see if that works..

THanks

Joe

Re: /dev/pty

joe_91 — Thu, 01 Feb 2007 21:52:21 GMT

Question.. i can run the insf -e -d pty -n 2000 on the production machine right? I assume no impacts..

Thanks

Joe

Re: /dev/pty

Bill Hassell — Thu, 01 Feb 2007 22:29:22 GMT

Yes, you can run insf on a production system. It just creates the missing device files. PTY devices are the one area where SAM works really well. The 3 kernel parameters for remote connections are:

npty
nstrtel
nstrpty

But setting these parameters to another value is not the complete task. The number of device files for these parameters must be created, something that SAM does automatically. Note that 60 is the default value for the parameters and the device file count. Be sure you set all 3 parameters equally.