[PLUG] Query related to Process Table overflow

[Mandar Vaze]

Hi,

We are running into an issue where users are unable to login to the
RHEL 4.7 machine even via console.
Both username and password are accepted, and then after a while users
are returned to the login prompt

Here is my "theory" :
I suspect that this may be the case of Process Table overflow, where
OS is unable to create a new process.
In order to login the user, after password verification, OS needs to
provide an interactive shell to the user
If the Process Table is full, no new process can be created including a shell.
But all the existing processes would continue to run - hence the login prompt.

Query:
1. How do I prove or disprove my theory ? The big problem is that I
can't get "into" the system to troubleshoot, and the problem goes away
after a reboot.
2. How do I "catch" a rogue process (which may be forking too many
processes resulting into PT overflow)
3. How do I prevent this from happening in future ?

Regards,
-Mandar