Re: Lack of Semaphores

steve.adams_at_ixora.com.au (Steve Adams) writes:

> Hi Rick,
>
> On some platforms Oracle needs to get contiguous semaphores. Therefore "if the
> semaphore clients are not always shut down and started up in strict sequence,
> then an extra allowance [in SEMMNS] at least equal to the largest single
> requirement is recommended." Quote from p9 of my book.

Except I don't think that's the case on Solaris. Oracle seems to prefer allocating all its semaphores in a single set which presumably allows it to do what it calls vector posts.

But if the set size is too small it will happily allocate semaphores in multiple sets.

However SysV semaphores have the problem that need to be manually removed by the programs that create them. It's possible Oracle didn't remove them when you did the shutdown abort.

Using ipcs -a as root would let you see what semaphores are allocated and in how many sets they're allocated.

-- 
greg