SUMMARY: Oracle problem on Solaris 2.6

From: Chad Campbell (
Date: Wed May 17 2000 - 08:34:15 CDT

Does anyone have experience with the following error:
oracle error ORA 7279 - spcre:semget error, unable to get first
semphore set; followed by SVR4: Error:28: No space left on device.
We suspect that increasing our kernel semaphore limits might fix this,
but I'd like some other opinions.

It turns out that our original assumption was correct, and we needed to
increase our available semaphores. In our case we ended up needing to
increase shmmax as well, as someone apparently left of the last digit,
leaving us with 10% of what we need. Here are the parameters affected:


A few people pointed out that the PROCESSES parameter could be set too
high in the init.ora file.

Also, thanks to Julie Fisher, who gave me the method for calculating
some of the values:

semmns needs to be set to at least : (instances processes
{smon,psmon,dbwr,lgrw,arch,any other} * number of instances) + (the
value of
the PROCESSES parameter in the init<sid>.ora file) + (system processes
other non-Oracle applications).

semmsl needs to be set to the value of the PROCESSES parameter in the
init<sid>.ora file. If you have more than one instance and the values
the PROCESSES parameter are different, make semmsl equal to the lowest
PROCESSES so that you don't allocate semaphores that will not be used.

Additional thanks to:
David Evans
Todd Herr
Terry Parn
Ken Weschler
Fernando Nantes de Souza
Viet Hoang
Jonathon W. Ross
Steve Boronski
Ray Trzaska

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