in reply to Re^4: No child processes - system limit?
in thread No child processes - system limit?
27968 seems large enough... (or do you really have that many processes?)
On some older linux systems, this is set to 999, which is somewhat closer to potentially becoming a problem. (BTW, this value does not necessarily correspond to what is reported by ulimit — which is why I asked.)
The other cause for a fork to fail is insufficient memory (presuming the "waiting for a non-existent child"-theory I mentioned above). So, is the memory usage actually close to the limit when the problem occurs?
I'll take a closer look at the other conf settings to see if anything jumps out at me (not that I would know what every single one of them means... :)