<span class="html">Want to avoid segmentation with  apc.shm_segments?If your linux server limits the shared memory block  size and you're forced to use apc.shm_segments instead, change the  setting by using (here is 512M but change it as you like):
# sysctl -w kernel.shmmax=536870912

(but if you want the change to be permanent after a restart you would have to add the following line in /etc/sysctl.conf

kernel.shmmax=536870912)

and updating apc.ini

apc.shm_segments="1"
apc.shm_size="512"

apc.stat is an extremely important setting for a production server,  especially if many files are accessed on every request, which is quite  normal on complicated web applications.

Always aspire to use:
apc.stat="0"
so that APC does not try to check that each and every file exists on  every request you make. It also means you can update files on your  server without crashing incoming requests on that time fragment.  Whenever you wish to force APC to re-read all the files, simply clear  the cache or restart your server.</span>