topic Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading in Operating System - HP-UX

Server refused to allocate pty , ttytype: couldn't open /dev/tty for reading

adr33 — Thu, 12 Jan 2012 15:09:49 GMT

Dear all,

I have hp-ux server with 11.11 OS version, Today with suddenly I can't remote my server with telnet or putty (ssh) eve ftp.

But I can use it well with terminal (directly through server).

I've checked the syslog.log and found this below:

error:openpty:Bad file number

error:session_pty_req:session 0 alloc failed.

I've read some articles in this forum and try to restart my server but not solve the problem,

Anyone can tell me what happen to my server? it's a bug or something else?

Thanks

Best Regards

Adrian Tjahjana

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Dennis Handly — Fri, 13 Jan 2012 02:21:25 GMT

>suddenly I can't remote my server with telnet or putty (ssh) even ftp.

What does kmtune(1m) show for npty nstrpty nstrtel?

You may need to use SAM to make these larger.

Re: Server refused to allocate pty , ttytype: couldn't open /dev/tty for reading

adr33 — Fri, 13 Jan 2012 01:02:19 GMT

Hi how I can show kmtune(1m) for npty nstrpty nstrtel? Thanks

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Dennis Handly — Fri, 13 Jan 2012 02:20:50 GMT

>how I can show kmtune(1m) for npty nstrpty nstrtel?

Check the kmtune(1m) man page:

kmtune -q npty -q nstrpty -q nstrtel

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

adr33 — Fri, 13 Jan 2012 06:43:22 GMT

Hi, here's the parameter, anything wrong? Parameter Current Dyn Planned Module Version =============================================================================== npty 60 - 60 nstrpty 60 - 60 nstrtel 60 - 60

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Dennis Handly — Fri, 13 Jan 2012 23:33:32 GMT

>npty 60 - 60 nstrpty 60 - 60 nstrtel 60 - 60

Do you have more than 60 people trying to log on? You may have to use SAM to increase these limits.

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

adr33 — Sat, 14 Jan 2012 08:06:23 GMT

no it's only for around 50 users no more than 60, after I reboot the server the problem still occur.

it's corrupt maybe?

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Dennis Handly — Sat, 14 Jan 2012 22:47:29 GMT

>after I reboot the server the problem still occur.

If you are going to reboot anyway, you might as well use SAM to increase these kernel parms.

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Bill Hassell — Mon, 16 Jan 2012 03:30:02 GMT

... no it's only for around 50 users no more than 60, after I reboot the server the problem still occur.

it's corrupt maybe?

60 is the default and is way too small for 50 users. Every time a user logs in, you need a pty pair. This also includes all the junk logins caused by users that don't log out properly. Change all 3 parameters (npty, nstrtel and nstrpty) to 200, perhaps 500. There is no reason to have the system jam up due to a very small kernel parameter. By changing all 3 to a large value, you won't have this problem in the foreseeable future.

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

adr33 — Thu, 19 Jan 2012 04:44:51 GMT

Hi,
finally I restore the ignite and not to increase the kernel parms and the problem is solve, before the problem occur my /tmp file going to be 100% and the problem occur after that. It because of full space of tmp folder?

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

Dennis Handly — Thu, 19 Jan 2012 05:21:55 GMT

>It because of full space of tmp folder?

Running out of space in /tmp can cause all types of problems, including not being able to logon, especially if / is full. (Which sounds like your problem.)

I'm not sure why it mentions /dev/tty if /tmp is full?

Re: Server refused to allocate pty, ttytype: couldn't open /dev/tty for reading

adr33 — Thu, 19 Jan 2012 09:48:50 GMT

no idea about the relationship between them, but I can connect through my server before /tmp is 100 %. Not sure why it can be 100% suddenly. I've searched the issued about /dev/tty things and you're right it about to setting the parameter. I've checked too and I see that my DAEMON is failed to start when I reboot the server