What is accessing my storage?

[Pasquale61]

Is there an easy way to see what is accessing my RAIDZ2 volume every 10 seconds or so? (The 10 seconds is a rough guess.) The reason I ask is because on a regular basis, I can see and hear all 5 of my drives being accessed momentarily, in what appears to be on a regular interval. (All 5 lights flicker for a couple seconds.) I've never stuck around long enough to see how long this goes on for, but I see it happening more often than not.

This is my home system with nobody attached when this happens. I have two plugins that I tried disabling to see if they were causing this. (Plex and Crashplan) I tried with the powerd daemon on and off and that didn't make any difference.

My primary use for this is for a home media server that I want to keep on 24/7, so I would like to make this as power efficient as possible.

Is this normal behavior? Any ideas on how I can see what is causing this?

Here is my system:

FreeNAS: 9.3 Stable w/latest updates

MB/CPU: ASRock C2750D4I 8-core Intel Avoton
Disk: 5 HGST Deskstar NAS 4TB H3IKNAS40003272SN (RAIDZ2)
Boot Drive: SanDisk Cruzer 8GB USB
RAM: 32GB ECC (CT2KIT102472BD160B x 2)
PS: ST45SF-G
Case: DS380B

Thanks!

 

[Ericloewe]

.system dataset most likely.