This article describes what "SERVER=-YES" in the /etc/hostconfig file does in Mac OS X Server.

Symptom

In Mac OS X Server n the /etc/hostconfig file there are two servers, "QTSSERVER" and "AFPSERVER". If either of these servers is on then "SERVER=-YES" is used later in this script.

Affected Products

• Mac OS X Server

"SERVER=-YES" does several things. The most noticeable is that it may require your computer to automatically reboot and change to boot command as discussed in the following article:

Article 60173: " Mac OS X Server: Sometimes The Computer Restarts Itself During Startup "

If "SERVER=-YES" is in the script, the boot command is changed to include "srv=1". This causes the kernel to reserve half of the physical RAM to be used as buffer cache for these servers. The maximum reserved RAM will be 250 megabytes. For example, a server with with one gigabyte of RAM will have a buffer cache of only 250 megabytes, and a server with 256 megabytes of RAM will have a buffer cache of 128 megabytes. This is in contrast to the "SERVER=-NO" when only 3% of the RAM is reserved for the buffer cache.

This is necessary because both the QTS and AFP servers require a large buffer cache for best performance.