Thanks for the walkthrough. One particular comment: > "Nginx's fastcgi and proxy caches just store the static-ified versions of dynamic content in flat files,

Thanks for the walkthrough. One particular comment: > "Nginx's fastcgi and proxy caches just store the static-ified versions of dynamic content in flat files, and those files are accessed via the file system, which means they get cached into RAM whenever the file system decides they get cached into RAM. I had the free RAM, and Varnish's RAM-first approach felt like it would be faster." The pagecache should do a pretty good job holding file contents in memory for you! https://tldp.org/LDP/sag/html/buffer-cache.html https://tldp.org/LDP/sag/html/buffer-cache.html I haven't had to tune for this scenario, but I think this might be the one place where you want a high swappiness (and some swap spaces). This will let Linux move unused bits of memory into swap & let even more ram be used for pagecache.