Semaphores

If the number of semaphores is too low, HADB can fail and display this error message:

No space left on device

This can occur either while starting the database, or during run time. Since the semaphores are provided as a global resource by the operating system, the configuration depends on all processes running on the host, and not the HADB alone. In Solaris, configure the semaphore settings by editing the /etc/system file.

To run the nodes, NNODES (the number of nodes submitted implicitly by --hosts option to the HADB) and NCONNS connections (HADB configuration parameter NumberOfSessions, default value being 100) per host, use the following semaphore settings:

set semsys:seminfo_semmap = <default=10> + NNODES
set semsys:seminfo_semmni = <default=10> + NNODES
set semsys:seminfo_semmns = <default=60> + (NNODES * 8)
set semsys:seminfo_semmnu = <default=30> + NNODES + NCONNS

If you plan to run multiple nodes per host, make sure semmap = NNODES. Use the sysinfo and sysdef commands to inspect the settings.