> I'm assuming whatever file system is on the disks...

Netflix uses UFS+J on FreeBSD 10.

Here are some notes from their talk at NYCBSDCon 2014:

- 400,000 stream files per appliance.

- 5,000 - 25,000 client streams per appliance.

- 300 - 500 streams coming off each disk all the time.

- Attempt to buffer 1MB ahead, but caching is futile.

- Result is completely random disk workload.

- System becomes limited by disk latency and CPU load.

Video here: https://www.youtube.com/watch?v=FL5U4wr86L4