Hello there! First of all, you have to excuse my lack of knowledge. Linux is really not my area of expertise which is why I ask for help from people who know much better than I do.

So the story goes, I wanted to host a wordpress site. I found out there is a turnkey wordpress appliance for it, well simple enough I thought. So I downloaded it and imported it to my Virtualbox. Got it up and running without issues and have been using it for a few weeks without a single problem.

However, 3 days ago the site just went down. I check my virtualbox and it said it is out of both RAM and SWAP (checked through the use of the  'top' command). Weird I thought. I tried to restart it, but it refused to respond to any commands. I forcefully closed it in virtualbox (might been a bad idea.. but yeah.) and tried to start it again. No luck, it locked up and just stood there forever reading/swapping to my harddrive and didn't work at all.

At this point, I had no idea what the problem was. 

What I did was to exported the appliance in virtualbox to try and start it on another computer, and there it ran. But man it was slow like heck. But it ran.
Since it 'worked', i yet again imported the newly exported wordpress appliance to the server machine again. It ran, but again, slow.
After a while I noticed it is running out of RAM again for some reason. Without knowing what to do, i changed it to 1024MB of RAM instead of the normal 512MB (in virtualbox that is). After this it has been running for 3 days now, but it is using so much more RAM than before.

According to the top command, it is currently at 280MB free out of that 1024MB that I gave it. Which is a lot less than the 400-450MB of free RAM it had 24 hours ago.

I still have no idea what is causing it and honestly, i don't really know how to figure it out. I don't know why one day it just crapped out like that. Which is weird since neither me or my girlfriend touched it for days around that period.
It feels like it is slowly eating through the RAM now as well, considering for every hour it is up, i get a little bit less of free RAM. I had 350MB free this morning, and now about 14 hours later I have around 280MB of free RAM.