HP-UX Host Intrusion Detection System Version 4.1 Administrator's Guide

Enabling More than 23 Agents (Thread Limits)
You must ensure that the administration system provides enough threads per process
to handle the maximum number of agent systems you will monitor at one time. The
thread value is specified by the tunable kernel parameter max_thread_proc. You
can compute its minimum value using the following formula:
max_thread_proc = 2 * <num_agents> + 18
Where: num_agents is the number of agent systems to be monitored.
By default, max_thread_proc is set to its minimum value, 64, which allows for 23 agents.
The maximum value of max_thread_proc is governed by the configurable kernel
parameter nkthread, which you can increase if you have a larger number of agents.
NOTE: The max_thread_proc is a dynamic tunable in HP-UX 11i version 1.6 and later.
In earlier versions of HP-UX, a change to this parameter requires a reboot.
The max_thread_proc tunable can be modified using SAM (on HP-UX 11i v1 and HP-UX
11i v2 operating systems) or SMH (on HP-UX 11i v3 operating systems). Based on your
operating system version, follow one of the procedures listed below to modify this
tunable:
Procedure 2-6 To change the value of max_thread_proc on HP-UX 11i v1 and HP-UX 11i
v2:
1. Launch sam, the HP-UX System Administration Manager (SAM).
2. Select Kernel Configuration.
3. Select Configurable Parameters .
4. Highlight the max_thread_proc parameter.
5. Select Actions > Modify Configurable Parameter.
6. Enter your new value in the Formula/Value box.
7. Select OK.
Your new value shows in the Pending column.
8. Select File > Exit.
9. If you changed the value create a new kernel and reboot. Follow the steps provided
by SAM.
NOTE: In HP-UX 11i v2, the modification of kernel tunables and kernel configuration
was moved from SAM to the kcweb system configuration interface. For more
information, see Managing Systems and Workgroups: A Guide for HP-UX System
Administrators for details.
Procedure 2-7 To change the value of max_thread_proc on HP-UX 11i v3:
1. Launch smh, the HP-UX System Management Homepage (SMH).
2. Select the max_thread_proc parameter.
48 Configuring HP-UX HIDS