Is your Mac OS X server crashing frequently? If so, we have two questions for you:

Question 1: Do the crashes, restarts, or slow downs occur primarily when several people are searching server volumes over the network?

Question 2: Are you running Mac OS X Server 10.4.7 or later?

If you answered yes to both these questions, you may be suffering from a problem that exists in Mac OS X Server 10.4.7 and above where multiple Spotlight searches can render a server unresponsive.

The Good News, and the Bad News.

The good news is that there is a fix for this problem — we are regularly correcting this issue on most of the Mac OS X Servers we support. The bad news is that the fix requires editing hidden text files through the Mac OS X terminal. That’s more than we generally get into in this tips collection — and should only be applied by someone fairly versed in the Unix command line.

In this tip, we’ll describe the problem. We’ll provide enough information for someone with the proper experience to apply the fix. And we’ll encourage you, if you are experiencing these problems, to forward this tip to your computer support team to apply on your server.

The Problem: Spotlight and Crashing Mac OS X Servers.

When your creative teams searches a shared network volume, your Mac OS X Server sets aside some RAM for that search activity. As more people search, the server sets aside more RAM. Mac OS X Server will continue this way until it has set aside about 2GB of RAM.

Our crashing problems surface on severs with less than 4GB of RAM. It turns out reserving that much memory for Spotlight searches doesn’t leave much room for everything else your server needs to do. This results in your server performance degrading, or the server becoming unresponsive, and even restarting unexpectedly.

You can confirm this problem may be occurring on your sever by using Apple’s Activity Monitor utility. Look for a process named “kernel_task” with a process ID of 0. If this kernel_task is taking a large amount of real memory (over 1 GB) then you are probably suffering from this problem.

The Fix: Editing the /etc/rc.server file.

The fix requires changing your server’s preference so that it reserves much less memory for these Spotlight searches. This one change prevents your studio’s searches from eating up your server’s RAM, and crashing the system.

Apple has published a technote that describes the changes that must be made to the /etc/rc.server file. Apple wisely describes what changes need to be made to this rc.server file, but does not provide step-by-step instructions about how to make those changes. In other words, if you don’t know how, you shouldn’t be the one doing it.

Apple Technote 305167 — Mac OS X Server 10.4.7 and later may become unresponsive when clients search mounted network volumes.

If you are not ready to dig beneath the hood with terminal commands yourself, we recommend you forward this tip and the Apple link to your Mac support team.

If you are in the Seattle area and don’t have a good Mac support team, consider inviting Creativetechs out to your studio for a free introductory meeting.

Source: This tip inspired by the persistent sleuthing of Creativetechs’s server guru Jordan Bojar who brings ten years experience as a Unix-geek in high-end server farms.