On 2/3/2014 12:59, m.roth at 5-cent.us wrote: > Kwan Lowe wrote: >>> Mem: 1361564k total, 1264324k used, 97240k free, 8428k buffers >>> >> That doesn't look like a lot of memory.. Possible to add another .5G or >> so? > > Ah! I missed that. Is it actually the case that your server doesn't even > have 2G of RAM? That's a *real* problem. Small RAM limits with strange values like 1.3 GB are normal for VMs. Rather than give the VM more dedicated RAM, have you tried adding more swap, Jussi? Your system may be well-tuned, not I/O bound all the time swapping to disk, but that doesn't mean swap isn't useful. Modern OSes pretty much depend on having some swap space. If nothing else, it lets the OS move some little-used bits of code out of RAM, so the RAM can be used for the computer's real work. Many web stacks are RAM pigs. I don't mean "they can use a lot of RAM productively," I mean they're based on inefficient or misapplied technologies that load a bunch of pointless things into RAM. Unless these things get swapped back out, they're ballooning your VM for no useful purpose. One web stack I used in the past had *GUI libraries* linked into its core executable. This, for software designed to run on headless VPSes! Another thing to look into is how many forks or threads your web stack uses. More is better for speed, up to the point where you run out of RAM, at which point your web stack slows to a crawl or dies. If each fork takes 500 MB, and you've got it set to use 3 forks, you're already running into swap space, unless there's some serious RAM sharing going on among the forks. That's another aspect of web stacks being RAM pigs: it is *possible* to make a pre-forking web stack share a lot of RAM among the forks, but it doesn't happen by itself. If you use naive defaults and naive development practices, you can end up with each fork being essentially independent copies of the whole web stack. This not only chews up RAM to no good end, it means each fork takes longer to start, which hurts site performance. Web site tuning is hard.