Forum OpenACS Q&A: VPS hosting and memory requirements

Posted by Jeff Rogers on
I'm looking at setting up a small openacs server for experimentation, and since the last time I checked the prices on low-end linux VPSs has come way down - I found at least one place offering a 256MB VPS (OpenVZ I assume) for $3/mo. Looking at my locally running install between nsd and postgres processes the memory footprint is really close to that, but memory footprints can be hard to get a true picture of due to sharing and whatnot.

Has anyone successfully configured OpenACS to run in this kind of small-memory environment? The first things I'd look at tweaking are the threadcount and number of db connections. I tried using ttrace a few years ago, but without much luck.

I am looking at plain VPS hosting right now, not expecting anything preconfigured. And I also understand for this kind of low-end VPS there could be some stability and/or performance issues (especially if the server is badly overcommitted). But this is primarily for a personal site experiment; for a real site I'd expect to pay real money for hosting.

(BTW, there are bunch of threads on this topic, but all of them are several years old. Maybe things have changed a litte? :)

Posted by Patrick Giagnocavo on
I think you would be happier with 512MB at a minimum; it does depend on the kind of virtualization the VPS provider supplies.

If the VPS is fully-virtualized like Xen or VMWare, where the VPS is wholly a different machine, then the 256MB RAM size is too small as you want to have a little bit of RAM free for disk caching and other tasks.

If the VPS is partially virtualized with something like OpenVZ, which uses a single kernel for all VPSes but has barriers between VPSes, then the host OS will do disk caching.

What technology the supplier is using should never be a secret, so just ask them. Amazon AWS uses Xen if I recall correctly.