Weird php error, firewall is down

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I have pfsense firewall setup at a customer site. Initially openvpn stopped working. I ssh'd in and saw the errors below. At that point networking was still working. I rebooted the firewall and it stopped working completely.  I went to visit the customer and see the php error below.  I am wondering what caused this to happen. The only thing i can think of at the moment is that memory stick its installed on is going bad, but then again I am able to get to a prompt via serial console

Any ideas?

Fatal error: PHP Startup: apc_fcntl_lock failed: in Unknown on line 0
PHP Fatal error:  PHP Startup: apc_fcntl_unlock failed: in Unknown on line 0

Fatal error: PHP Startup: apc_fcntl_unlock failed: in Unknown on line 0
PHP Fatal error:  PHP Startup: apc_fcntl_create: open(/tmp/.apc.iApST5, O_RDWR|O_CREAT, 0666) failed: in Unknown on line 0

Fatal error: PHP Startup: apc_fcntl_create: open(/tmp/.apc.iApST5, O_RDWR|O_CREAT, 0666) failed: in Unknown on line 0
PHP Fatal error:  PHP Startup: apc_fcntl_create: open(/tmp/.apc.7b4J4c, O_RDWR|O_CREAT, 0666) failed: in Unknown on line 0

Fatal error: PHP Startup: apc_fcntl_create: open(/tmp/.apc.7b4J4c, O_RDWR|O_CREAT, 0666) failed: in Unknown on line 0

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[SOLVED]  -  It was the USB disk that went bad.  I put in a new one and restored the config and were back in  business.