Getting "Server refused to allocate pty" upon login attempt

Problem(Abstract)

You are unable to log into AIX because the maximum number of pseudo-terminals have already been allocated.

Symptom

An attempt to log into AIX via telnet or ssh results in this error:

"Server refused to allocate pty"

- You have increased the maximum number of ptys but you still see the problem.
- Each time you log in, the pty number increases and the pty numbers are not getting released and re-used.

Diagnosing the problem

The symptoms may indicate that there is an application that is holding on to ptys and not releasing it.

Try using the 'fuser' command to find the culprit application, like this:

# cd /dev/pts
# fuser *

The 'fuser' command will list all PIDs associated with each pty device.

If there is a process that is not releasing its ptys, you will see its PID occur many times in the fuser output above

Resolving the problem

Restarting the application that you diagnosed above should release all the ptys held by that application. Contact the application vendor support to see if there is a patch or configuration for the problem.