Before you read this, please note that I understand the benefits of caching. I'm familiar with the dogma that unused ram is wasted ram.
This question is one that I've adapted from a previous question:
In that question I was curious about adjusting how my server uses and caches ram. The system is fairly dynamic so I believe that the cached files doesn't really afford me much gain. Additionally, we have code on the server that has to quickly access large amounts of ram in short periods of time to process video files and I believe that I'll see a performance benefit from directly handing of ram rather then clearing it from cache and then handing it off.
I'd like to find out if any of you have experience with adjusting the default value of 60 in the following file (this happens to be on an Ubuntu server):
And if so, what affects did you see. If I replace the default value of 60 with 30 will I see less swapping and a lot more reuse of stale cache? Do I approach 0 or 100 to decrease swapiness and increase reuse of cache?
Finally, anyone know why the default is set to 60?
NOTE: If it's close to 0, Linux will prefer to keep applications in RAM and not grow the caches. If it's close to 100, Linux will prefer to swap applications out, and enlarge the caches as much as possible. The default is a healthy 60. - Thanks for the link below, 3dInfluence.