How much free memory should I have on my webserver?
- by neanderslob
I have a webserver that's currently hosting two Wordpress sites and some java-based collaboration software. The server has 2G of memory and is currently using about 1.8G of the available memory. Right now what's on here is pretty much a pilot project that's getting negligible traffic so I think it's pretty clear that I'll be needing more memory.
I was wondering, if I was to release it, how I might anticipate my memory needs based on the traffic it gets. I've poked around on Google and what I've found has been a bit tenuous. Is there a good heuristic that one should use when calculating memory demands as a function of the base (no traffic) load on the server?
For reference, the output of free -m can be seen below:
total used free shared buffers cached
Mem: 2048 1832 215 0 0 0
-/+ buffers/cache: 1832 215
Swap: 0 0 0
To me this looks like actual memory used and isn't an illusion due to caching or anything else.
I figure the demands of my collaboration software will have to be experimentally tested so here's free -m without that software running:
total used free shared buffers cached
Mem: 2048 1109 938 0 0 0
-/+ buffers/cache: 1109 938
Swap: 0 0 0
My plan B to figure this out is to add a bunch of swap space to the server, give it some traffic and adjust according the the amount that swap gets used. I was just wondering if anyone had a good rule of thumb to estimate how much memory I should plan on in advance...or if what I'm thinking is nuts.
Many thanks in advance (I'm really quite new to this).
