SUMMARY: logins: how to create additional pseudo devices

From: Christophe DIARRA (
Date: Fri Sep 13 1996 - 12:30:15 CDT

Dear sun-managers,

I received a lot of good answers about how to increase the number of
pseudo-devices to allow more connections with xdm, telnet, rlogin.
You can find the original request at the end of this mail and also two
of the mails I have received: the first one is from
Steve <> and the second from
Scott Swoboda <>. This two mails are good
summaries of all the answers.

Many thanks to:

David Lee <>
Ray Trzaska <>
Daniel Lorenzini <>
Trevor Paquette <>
Normand Ranger <rangern@CIRANO.UMontreal.CA>
John Benjamins <johnb@Soliton.COM>
Stephen Harris <>
John R Worachek <>
Scott Swoboda <>
David R. Steen <>

My apologies if I missed any one who replied.


Christophe DIARRA
Institut de Physique Nucleaire
91406 ORSAY Cedex
Tel: (16 1) 69 41 65 60

************************ START OF THE SUMMARY SECTION *************************

To create more devices in /dev/pts:

1) set pt_cnt and npty to the same value in /etc/system file.
   Steve ( says that I have to
   set sadcnt and autopush too (his mail will follow the summary section):

   Some people think that 256 is the max value of pt_cnt but I was able
   to create 512 devices in /dev/pts by setting pt_cnt to 512. I think
   I will reduce it to 128 a value suggested by many people.

2) reboot the system with 'boot -r' or create /reconfigure
   ('touch /reconfigure') before rebooting. BUT it is possible to create
   more devices without rebooting: just run 'drvconfig -r /devices' and then
   'devlinks' (see the mail of Scott Swoboda).
************************ END OF SUMMARY SECTION *****************************

MAIL from

This needs to go into /etc/system. This will give you 256 devices. sadcnt
must be 2x the devices. This can be changed to support whatever number of
devices you need.
You then need to boot -r or touch /reconfigure and reboot. Hope this helps
set pt_cnt=256
set npty=256
set sadcnt=512
set nautopush=256

MAIL from Scott Swoboda <>

when you reboot the system you have have a reconfigure file in /
or you need to do a boot -r from the console
Else try drvconfig -r /devices
then devlinks
this usually works on our systems

Original request

Subject: Re: logins: how to create additional pseudo devices
Hello managers,
I have only 48 devices in the directory /dev/pts. How can I create more
devices ? The system is rejecting connections (xdm, telnet, rlogin) because
there are no more devices.
After adding the line 'set pt_cnt=512' in /etc/system and rebooted the
system the problem still appears after some hours.
The system is a SS1000E with 128 Mb running Solaris 2.4.
Thanks in advance.

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