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How many CSM vps are created ?

Technote (FAQ)


How many CSM vps are created for SPWDCSM and ENCCSM?


If you encrypt password using simple password communication support module (SPWDCSM) or enable network encryption using the encryption communication support module (ENCCSM), IDS server creates CSM vps. The number of CSM vps depends on the number of CPU vps configured. Server creates one vp for each CPU vp configured for each encryption method.
For example:
If you have 70 CPU vps and have both encryption methods configured then server will create 70 CSM vps for ENCCSM and 70 CSM vps for SPWDCSM.

This is important to know because server can run out of semaphores when it tries to create vps and you will see this error in online.log file.
semget: errno = 28
create_vp: cannot allocate semaphore

Workaround for this issue is:
1. Bring up the instance with low cpu vps.
2. Start connections so csm vps will be created.
3. Add the rest of the cpu vps dynamically.
Increase semmni and semmns so server does not run out of semaphores.

Document information

More support for: Informix Servers

Software version: 11.70, 12.1

Operating system(s): AIX, HP-UX, Linux, Solaris, Windows

Software edition: Developer, Enterprise, Express, Growth, Hypervisor, Innovator, Ultimate, Workgroup

Reference #: 1677759

Modified date: 04 May 2017

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