updated 04:05 pm EST, Tue January 13, 2009
AFP server problems
Problems with Mac OS X Server are causing some corporate networks to come to a crawl, complaints from network administrators indicate. The problem is believed to stem specifically from Apple File Protocol, as used by Mac OS X Leopard Server; whereas Leopard typically consumes only a portion of the CPU power on an Xserve, some administrators have noticed quad- and eight-core Xserves becoming non-functional due to AFP activity. CPU burden can become as bad as 800 percent, according to one complaint.
The exact reason for the AFP overloads is unknown, and their appears to be no permanent solution to the problem, whether from Apple or an independent source. Killing processes and/or restarting a server is necessary for recovery; some administrators say they have managed to reduce server load by adjusting the afp_wan_quantum and afp_wan_threshold variables on a server, and killing unnecessary processes or tasks.