NAS storage solution for photographer with multiple editors?

A cache only improves performance...

There is 3 characteristics of storage we need to keep in mind when we talk about storage performance.

  1. IOPs
  2. Bandwidth
  3. Latency.

IOPs is for scalability. You can have more concurrents users, applications, files operations.
Bandwith is the amount of data can push or pull from you system at the same time. It s the data throughput.
Latency is the response time between two I/O.

Mechanical hard drives has poor latency (3~15ms latency,) very low IOPS (~150 IOPs) but good throughput and very good capacity for the price. They are good only in sequential workload (reading, copying big files) with very few concurrents access (very low IOPs).

SSDs have high IOPs(30 000~ 90 000 iops ) very low latency (30 ns~1 ms). they are good in all type of workload (random, sequential) but has low capacity, shorter life and cost more.

So a mechanical hard drive is good only when one user is using it for copying or reading a limited number of big files.
A SSDs, at least an enteprise SSD, is build to handle a lot of differents applications, users, MVT\DVL8496

If you used only NAS based on mechanical hard drive, what you experienced with them was the very poor latency, and poor iops of your bunch of mechanical hard drives more than « network » (Expect on wifi).
Network matters but if you used wired network, you are supposed to have under 1ms. On WiFi, 3~10 ms.

To solve this, the industry began to use SSD/NVMe cache.

Why? Because they are f**** fast everywhere. In random (reading and copying a lot of little files) and sequential!

I ll talk only about enterprise grade SSDs/NVMe, because they are built to handle file server, database workload.

A file system, raid, that have a SSD cache will be used to convert all workfloads that a mechanical hard drive is not able to handle in a sequential one.

/r/HomeNetworking Thread Parent