Thanks for the replies. Well, trying to be more specific.

There is an MQ server running on the host, running ps -ef at any time shows about 90 lines of output. This is quite normal, including the processes belonging to AIX itself, the MQ server and the monitoring scripts (5 maximum at any given moment).

This morning I found that the output of ps -ef shows just the same amount of processes as it usually does. Most of them remain live for an extended period, thus every app that succeeded to connect earlyer, is able to use the service. New connections cannot be created - new connections in this configuration implies new processes to handle a client.

Also I am unable to run any command that is not setuid root.

Now, raising the maxuproc value from 4096 to 5000 seems to solve the problem. Well, there is not a single user in the system trying to run 4000 processes, as I see 90 processes altogether. Why?

Couple of hours later the problem is showing up again the same way. Raising the maxuproc again solves the problem. Well, seems solving. Something is accumulating in the background and I do not see what that might be. So, when I run into this maxuproc problem, and maxuproc is set to 4096, then I would like to see thet something is really 4096. What kind of objects are counted? entries in process table? Threads? Or what else.

Well, I know how to list user parameters .

The relevant parameters of the relevant user are:

Code:

        fsize=2097151
        cpu=-1
        data=262144
        stack=65536
        core=2097151
        rss=65536
        nofiles=2000

Well, yes, maybe I was on a wrong track and the limit was not the number of processes, but some other limit. In this case my question is, why did the raise of maxuproc suppress the problem?

--Trifo