Ubuntu 12.04 x64 ~ LEMP+WordPress: PHP keeps crashing

Hi folks,

I’m running a 512MB RAM droplet with 2 separate single WP installs. Both vhost configs are identical. One of them is very new with just 6 posts so far. The other has been around since Dec '12.

I need some help here. For the life of me, I can’t figure out why PHP keeps crashing. I had the same problem with PHP5.3 + APC. Now I’m on PHP5.5 with ZendOpcache. I have to keep checking my site every now and then and login via SSH to restart PHP. Doesn’t sound right to me.

i. repository ppa:ondrej/php5 ii. repository ppa:nginx/stable

If someone could take a look at my configs and let me know what’s not right, will be greatly appreciated. I’m new to VPS have moved from a cPanel Shared Hosting. I like to seed now and hate to return to shared hosting should things not work out for me.

1. /etc/nginx/nginx.conf: http://pastebin.com/A6GTZkwx
2. /etc/nginx/sites-available/mydomain: http://pastebin.com/GiiCLX0L
3. /etc/php5/fpm/php.ini: http://pastebin.com/AYQSae6v

I’m prepared to move the newer WP install to a shared host if required. I am currently not running W3TC or CloudFlare. I reckon I should be sorting out the crashing PHP before all else.