Ask HN: Disk based caching server?

I'm trying to find one or more articles I previously read from HN but haven't had any luck finding them today. They were on the topic of using caching built into filesystems/disks which has been improved for decades instead of trying build an application based caching system on top of that. I believe there were comparisons between some nosql or caching databases with one in particular being the example of the disk caching approach where the server in questions was simply a thin api layer on top of the filesystem. I may have some of the wording or facts mixed up but if this sounds familiar please point me in the right direction. Thanks