Under Solaris 2.6 (and probably other versions as well), the maximum number 
of shared memory segments is six. This means that on an out-of-the-box machine
you can only configure six rings. If you try to configure more than that, you
will see a cryptic message from tport_create about too many open files.  The
fix to this problem is to add the following lines to the /etc/system
file, and then reboot the system.

 set shmsys:shminfo_shmmax = 4294967295
 set shmsys:shminfo_shmmin = 1
 set shmsys:shminfo_shmmni = 100
 set shmsys:shminfo_shmseg = 20
 set semsys:seminfo_semmns = 200
 set semsys:seminfo_semmni = 70

This allows for 20 rings.