How much free memory(RAM) should I have on a VPS?

[Jovani]

Hi,

Anyone gives me advice on how much free memory(RAM) should I have on my VPS to keep website run well all the time?

thanks in advance
Jovani

 

[RDO Servers]

Hey Jovani,

The is no cut & dry answer to this. It depends on what your running on it, how many sites, what your typical usage is, etc.

You want to have enough free memory to handle any sudden spike in traffic, without degrading website performance.

If your website are mainly static, then you could easily double the traffic without too much extra memory usage. If you have a lot of dynamic content, caching, data stored in session state, etc then it will consume more memory as your traffic increases.

I would suggest looking at your memory usage with minimum site usage then compare this to your memory usage whilt you have a lot of visitors on the site. Take the difference, and double it. Theoretically this would allow you to almost double your traffic and still have enough memory to handle the load.

 

[Jovani]

Jovani

I don't think so, if my resource is using over 70% of RAM then my VPS can be downtime whenever if it loads more than 100% of RAM.

So, I should keep Memory Usage under 30% or 50% ?

 

[RDO Servers]

Yes, if you have 100% memory usage, you are going to have problems!

I would suggest keeping peak memory usage under 70% or less. We keep our server running at 40-50% memory usage. It cost us more, but is worth it to make sure there is always plenty of ram available. It all depends on how much your willing to spend and how critical it is to always have extra if needed.

 

[MightWeb]

It's very dependant on your usage, so there's indeed no clear cut answer. For some, spikes will never be more than +10%. For some, spikes can be 50%. We keep 40% RAM available at all times to allow for spikes, but then again, we span a lot of clients, and therefor need to account for their usage, which we can't be certain of apart from their own hard limits. If you're running the VPS yourself, then you should simply monitor it to see where your spikes are, and adjust your available RAM after that.

 

[Imbahost-Andy]

It really depends on what type of site your hosting and what scripts are running. It is very hard to determine but I recommend at least 40% Free RAM on the Server so that it can manage the occasional spikes without crashing your server.