topic Re: Reason: get_pty: not enough ptys in Operating System - HP-UX

Reason: get_pty: not enough ptys

Amit_Suchak — Tue, 08 Mar 2011 15:07:47 GMT

Hello Experts,
We have Server Model HP RX 2660 inetgrity with
HP-UX B.11.31 U ia64 itanium based system . Getting below error after 78 xterm sessions
xterm: Error 32, errno 16: Device busy
Reason: get_pty: not enough ptys
We have set below paramets already
kctune nstrtel nstrpty npty
Tunable Value Expression
npty 4000 4000
nstrpty 1000 1000
nstrtel (now) 60 Default
(next boot) 200 200

But stil getting same error . I have alreay increased nstrtel to 200 which will become after reboot , that we will do it tommrrow morning.Let me know what can be the issue causing this error.
xterm: Error 32, errno 16: Device busy
Reason: get_pty: not enough ptys

Awaiting response . Thank you

Re: Reason: get_pty: not enough ptys

Steven E. Protter — Tue, 08 Mar 2011 16:00:13 GMT

Shalom,

You must boot to get the nstrtel figure to go to 200 as you have set it.

There is no way around reboot.

There is no cost in setting it higher. I'd make it the same as nstrpty

Then boot, then all will be well.

SEP

Re: Reason: get_pty: not enough ptys

Jose Mosquera — Tue, 08 Mar 2011 16:09:14 GMT

Hi,

Just recreate automatically devices and y pseudo-drivers:
#insf -e

Rgds.

Re: Reason: get_pty: not enough ptys

Amit_Suchak — Wed, 09 Mar 2011 09:42:03 GMT

Hi,
after reboot & chaging all parametere to 1000 still users can not open xterms . it does not go beyond 81 sessions. Let me know anything need to be done further any other kernel parameter ned to change.

Thank & regards
Amit

Re: Reason: get_pty: not enough ptys

Jose Mosquera — Wed, 09 Mar 2011 10:16:40 GMT

Hi,

1) npty specifies the maximum number of pseudo-tty data structures that are available on the system.
Acceptable Values:
Minimum 1
Maximum Memory limited
Default 60

npty limits the number of the following structures that can be used by the pseudo-teletype driver:
struct tty pt_tty[npty];
struct tty *pt_line[npty];
struct pty_info pty_info[npty];

2)nstrpty defines the maximum number of streams-based PTYs allowed on the system.
Acceptable Values:
Minimum 0
Maximum Memory limited
Default 0

nstrpty limits the number of streams-based PTYs that are allowed system-wide. When sending data to PTY devices (such as windows), a PTY device must exist for every window that is open at any given time.

**nstrpty should be set to a value that is equal to or greater than the number of PTY devices on the system that will be using streams-based I/O pipes.** Using a parameter value significantly larger than the number of PTYs is not recommended. nstrpty is used when creating data structures in the kernel to support those streams-based PTYs, and an excessively large value wastes kernel memory space.

3) nstrtel specifies the number of telnet device files that the kernel can support for incoming telnet sessions.

Acceptable Values:
Minimum 60
Maximum
Default 60

nstrtel specifies the number of kernel data structures that are created at system boot time that are required to support the device files used by incoming telnet sessions on a server. **This number should match the number of device files that exist on the system.** If the insf command or SAM is used to create more telnet device files, the value of nstrtel must be increased accordingly or the device files cannot be used because there are no kernel data structures available for communicating with the system.

**Select a value for nstrtel that is equal to or greater than the number of telnet device files on the system.** Selecting a value that exceeds the number of device files actually existing on the system wastes the memory consumed by extra data structures, but it may be justified if you are planning to add more device files.

After modify these parameters, the kernel must be updated and reboot the system.
When the system is up, recreate all devices and y pseudo-drivers:
#insf -e

Are you opening your xterm session through an emulator (eg: Reflection-X)?
Yes: Do you see a dot files in the home directory where you do the export of TERM variable? Move them to a subfolder and retry.

Rgds.

Re: Reason: get_pty: not enough ptys

Amit_Suchak — Wed, 09 Mar 2011 13:42:55 GMT

Hi.
we are opening xterm thru Hummingbird excced . so is their anything to check in that case.
Regards,
Amit

Re: Reason: get_pty: not enough ptys

Viktor Balogh — Thu, 04 Aug 2011 18:06:30 GMT

duplicate!??

Re: Reason: get_pty: not enough ptys

Amit_Suchak — Thu, 04 Aug 2011 18:06:57 GMT

Hello Victor,
First i started new thread on my name
http://h30499.www3.hp.com/t5/Networking/Reason-get-pty-not-enough-ptys/m-p/4762753#M47332

As my requirement was urgent in need of solution later again i was searching for more solution i seen this thread from Leonardo Parrino another thread .. but in that also my problem was not solved
Now we can continue with my current thread only, where still I am searching my solution .. Thank for your guidance.

Actually i am trying to open xterm from another xterm from humming bird Exceed GUI application . so a that that after changing this 3 kernel parameter to 1000 but still its stuck at 81 . so just want to know if anything else also need to change.
Now i have increased this parameter to 4000 so it may increase that xterm
kctune nstrtel nstrpty npty
Tunable Value Expression
npty (now) 1000 1000
(next boot) 4000 4000
nstrpty (now) 1000 1000
(next boot) 4000 4000
nstrtel (now) 1000 1000
(next boot) 4000 4000

Attached is the list of 62 users which are logging in . But when this reached 82 in in xterm hummingbird exceed it gives error as below:-
xterm: Error 32, errno 16: Device busy
Reason: get_pty: not enough ptys xterm &
regards
Amit

Re: Reason: get_pty: not enough ptys

Amit_Suchak — Thu, 10 Mar 2011 10:02:59 GMT

Hello Experts,

Anybody has solution for my issue.

regards
Amit