Mac OS X Server (Universal) 10.4.7 through 10.4.10: May become unresponsive when clients search mounted network volumes

Issue or symptom

As clients search mounted network volumes, the kernel_task process (pid 0) on the server is allocated more and more RAM. System administrators may notice that the amount of RAM allocated to the kernel_task process may be close to 2 GB. On servers configured with 2 GB or 3 GB of RAM, this can result in server performance degrading, or the server becoming unresponsive, or restarting unexpectedly.

Solution

Update to Mac OS X Server 10.4.11 to resolve this issue.

If you are uable to update to Mac OS X Server 10.4.11 you can make following change to /etc/rc.server to improve performance in this situation. This is recommended only if your server has 2 GB, 3 GB, or 4 GB of RAM.

1. Make a copy of /etc/rc.server with this command:
   
   $ sudo cp /etc/rc.server /etc/rc.server.bak
2. As the root user, open /etc/rc.server in the text editor of your choice.
3. Locate this line in /etc/rc.server:
   sysctl -w kern.maxnbuf=90000
4. Change the number 90000 to 20000, so that the line reads:
   sysctl -w kern.maxnbuf=20000
5. Save the changes made to /etc/rc.server.
6. Restart the server.

reboot hang