Hi, I set up a web server recently with the instructions from the perfect server setup using Ubuntu 15.04+IPSConfig3+PHP5+MariaDB etc. I have some problems with slow server response time. The server is hosted at digital ocean. 2gb ram 2 cores KVM, upgraded from 1 gb ram earlier. It only has 5 Wordpress sites with no traffic at all. I've set up Cloudflare and browser caching using htaccess. When running top I see that there is generally a high memory consumption. This is ascreen shot from top: tinypic.com/ scup2d.png Thanks in advance
A high memory consumption is normal on Linux as the Linux kernel uses ram to cache data from the harddisk to make your server faster. The problems with virtual machines like the one you have from Digitalocean is that another vm from a different custmer that is hosted on the same hardware node can affect the performance of your vm. So your problem dont has to be in the setup of your server. When a cms system like wordpress is slow while you dont have a high server load, then this is often caused by a slow database, e.g. when the vm has not enough IO bandwidth or another vm on the same host uses too much IO Bandwidth. You can try to tune your mysql database with mysqltuner, this might help a bit. And you should install caching plugins in wordpress e.g. w3 total cache.
Thanks for the reply. I checked with my provider, but they couldn't see anything unusual there. Are there any common pitfalls or tweaks that has to be done after following the instructions?
No, there are no additinal changes required. The setup is used on ten thousands of servers, so it is tested and optimized alot.
Thanks, I was thinking about installing Varnish -- I've read some articles saying that's a good choice for running several Wordpress installs. Do you think that could be worth it?
Varnish is caching static files like CloudFlare, so installing varnish makes not much sense when you use CloudFlare already. Have you installed w3 total cache in WordPress like I suggested?
Ok, I see -- thanks for the clarification. Yes, I installed W3 cache, it seems to help a bit for repeat users, but it still seems like the time it takes to load the sites is slow.
Did you check with firefox developer tools which elements of the site load slow? Maybe the site load some external js libraries that are loading slow.
