Drive spindown prevented by other systems on network - why?

[seby]

Hi all,

I have searched around and asked in the IRC channel to no avail. My drives don't spin down when the system is properly connected to my router and switch with other systems running - however they do spin down properly when the system is running as the sole device in my home network.

I have 3 boxes running Freenas, each with basically the same setup (same mainboard, same ethernet card, using the mainboard's 6 SATA ports) with different drive sizes, ranging from 3 to 6 TB. The 6TB one is having these issues (box no.3).

If I start box no.3 on its own, with no network cable attached the drives spin down after a while and remain asleep. This also works if no other systems are running on my network (i.e. ethernet cable plugged in, no desktop pcs running, but also none of the other 2 Freenas boxes running). I have tested this in multiple ways, but cannot get to the bottom of WHAT is preventing my drives from sleeping when "online".

There are no mounts from the other Freenas boxes that would connect, but the sheer presence of them on the network seems to trigger some activity which in turn doesn't allow my drives to sleep.

Question: is there a way to monitor all ethernet traffic to and from my Freenas box no.3? And is there anyone understanding this just a slight bit?

Thanks everyone. :)

 

[SweetAndLow]

First I would like to say that this question gets asked all the time, search for other threads and see there solutions. The result of those other threads is always the .system dataset. This holds information for smb, and i have a feeling that the boxes are doing network discovery for smb which results in writes being made to the .system dataset and keeping your disks awake. If you put your system dataset on an ssd your hdd will sleep like you want. I would also like to add that usually the power savings you get from sleeping your drives doesn't outweigh the cost of replacing drives sooner from the extra wear and tear you are creating by spinning them down.