Web server advice
Guys, got a bit of a situation here and im looking for some input, short term and longer term.
Currently have a VM that we use for basic hosting after the physical machine we had used for years started to fail. Its a VMware instance with 512Mb of ram on a pretty high end blade system. Running Debian 6, Apache, PHP MySQL, ProFTPd, Webmin and Exim4.
There are about 50 domains, mostly low traffic, a handful of databases and one SSL site.
The problem is that the server keeps grinding to a halt and becoming unresponsive. The only options at this point is to force a power off from the VMware client and reboot it. From what the host is saying, there just isnt enough RAM for the system, which i find hard to believe, and when things like crawlers are hitting our sites its not able to cope.
Why is apache not just timing out, rather then trashing the whole system?
I did follow some config guides when i configured the server, but what would you guys recommend for configuring apache, php, mysql etc to get some stability right now?
I know switching over to Nginx will probably help no end, so i need to look at that i think. How do you migrate from an an apache config file with virtual hosts, over to nginx anyway?
For the record, this system has been running since april and was very stable to start with, but we have been having more and more problems recently and i just dont know what im looking for to sort it.
Would really appreciate any input as its giving me a real headache.