Note:
 * Be sure your kernel is built with "options SYSVMSG" and "options SYSVSHM".
   Cdrdao requires kernel with these options. 
 * If you want to use POSIX scheduling control for better scheduling,
   include 
    
        options             "P1003_1B"
        options             "_KPOSIX_PRIORITY_SCHEDULING"
        options             "_KPOSIX_VERSION=199309L"

   your kernel configuration. It provides rtprio based soft real-time   
   scheduling control.