High Processes Cause Semaphore Errors

I could not create a new Delphix virtual database because I kept getting semaphore limit errors. I ended up reducing the processes parameter value to resolve the issue.

I got these errors creating the new VDB:

ERROR : SQL> ORA-27154: post/wait create failed 
ERROR : ORA-27300: OS system dependent operation:semget failed with status: 28
ERROR : ORA-27301: OS failure message: No space left on device
ERROR : ORA-27302: failure occurred at: sskgpcreates

The processes variable was set to 3000 on production so Delphix tried to create the VDB with the same value. I reduced processes to 100 and the VDB came up cleanly.

I have been living with this problem for a year or two but yesterday I really needed to resolve it and I finally figured it out. I got the idea of reducing processes from this Oracle support document:

Instance Startup Fails With Error ORA-27154,ORA-27300,ORA-27301,ORA-27302 (Doc ID 314179.1)

I looked these errors up on Oracle’s support site several times in the past and never saw the idea of reducing processes so I thought I would mention it here if only to remind myself.


About Bobby

I live in Chandler, Arizona with my wife and three daughters. I work for US Foods, the second largest food distribution company in the United States. I have worked in the Information Technology field since 1989. I have a passion for Oracle database performance tuning because I enjoy challenging technical problems that require an understanding of computer science. I enjoy communicating with people about my work.
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