6.4. File System

Disks are disks are disks. They can also cause massive bottleneck problems that are difficult to solve if you need to store data on disk. While you can throw in faster disks (15,000 RPM SCSI drives anybody?), better RAID strategies (“striping”), and SSDs, there is still a limit you’re going to hit sooner or later.

The best strategy for this is to utilize memory-based caches for disk data where possible. Whether it’s the configuration file you have to read on every request, or the PHP files used to run the site, there are many options for this, and they all mean one thing: caching.