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.