on an amazon linux ami I've succesfully (I think) installed apc (with yum or pecl. tried both) but I'm not able to enable it (sorry for the pun).
php -i says:
apc
APC Support => disabled
Version => 3.1.15-dev
APC Debugging => Disabled
MMAP Support => Enabled
MMAP File Mask =>
Locking type => pthread mutex Locks
Serialization Support => broken
Revision => $Revision: 329725 $
Build Date => May 28 2013 18:03:40
Directive => Local Value => Master Value
apc.cache_by_default => On => On
(and so on...)
extension=apc.so and apc.enabled=1 are in /etc/php.d/apc.ini (and php -i confirm that /etc/php.d/apc.ini is parsed). I tried also to put them in /etc/php.ini to no avail. (And of course I dutifully restarted httpd every time). Now I really don't know what to do...
Apc is showing disabled , but did you check whether its working or not , as most of the time it shows disabled but works fine.
I installed the same in my centOS and checked that about the issue , me also getting the same output of php -i and but everything is working fine please see the below screen shot.