Hello, I've been running our litespeed server in workergroup mode since this morning with opcache disabled. No issues so tonight I manually installed ZendOpcache with 128MB per account and watched the error log. I kept getting a few lines like this : Code: 2013-11-16 18:53:47.793 [STDERR] fork() failed, please increase process limit: Cannot allocate memory 1) Cloudlinux memory limits are disabled 2) PHP memory limit is currently set to 512M 3) Zend opcache has the following settings : Code: opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 4) Total server memory consumption : Code: # free -g total used free shared buffers cached Mem: 251 196 55 0 33 110 -/+ buffers/cache: 52 199 5) Litespeed memory limits : Security > CGI Settings : Memory Soft Limit (bytes) : 150000M Memory Hard Limit (bytes) : 180000M External App : Memory Soft Limit (bytes) : 122880M Memory Hard Limit (bytes) : 163840M Do you have an idea what memory limit I'm hitting ? Is it the 512 MB for php being hit ? Is it a litespeed limit being hit ? (all litespeed limits mentionned above are larger than the 52 GB that were being used at the time. Or could it be a system limit ? Thanks.