I’ve turned off access time in ZFS. Why? What is access time? It’s on by default in most file systems, including ZFS, and basically it writes down when you last accessed a file. So even if you have a file system with only reads you’ll get writes updating the access time. This isn’t something I need on my file server, it just generates a bunch of extra writes with data (the access time) that I never use.

You turn it off by a simple command.

zfs set atime=off [pool name]

Hopefully it generates less writes, even though I’m not sure I’ll notice the difference.