Constant write activity on performance graph

Any ideas about this or do I need to ask Netgear?

Although know one may know why this happens, does anyone else see this behaviour?

NAS should save history for the Volume throughput graph once a minute. Deeps of the graph history can be 1 year. NAS is not idle this year. :-)

Thanks for the reply.
I don't understand what you mean.
The volume throughput graph shows continuous write activity, not intermittent.
This would effectively mean that when a disk spindown feature is introduced, spindown would never happen as there is never an idle period.
The graph is reset each time the NAS is powered off, which in my case is once a day.

vandermerwe, I'll try to explain what I mean.
Graph Utilization should check HDD and calculate volume utilization every minute even if NAS is idle. This mean HDD "read" activity on volume throughput graph.
If user didn't turn off NAS 365 days running (for example) then NAS should save performance parameters for each minute on volume for all graphs from performance page. This mean "write" HDD activity on volume throughput graph. The user will be able to check performance history with graph parameters: "Period", "Update".
HDD activity on volume throughput graph mean performance page activity. This is why OS6 based Netgear NAS does not have "Enable disk spin-down after" parameter as opposed to OS4 based NAS.

That explanation is plausible apart from the fact that there are very long periods where there is absolutely no read activity recorded, only write activity.

OK. My NAS is busy with backup currently. I'll watch this activity later

My backup job will take next 2 days. Simple idea. "Write" activity is not possible without "read" activity. Linux should read folder catalogue before writing operation at least.
vandermerwe, could you check "read" performance page with 5 mins period? May be reading activity is small but it is activity.

Definitely write activity and no read activity.
If I can figure out how to post a screen shot I will.
I've asked Netgear as well.

Strange, I agree that you should have some read too, for indexes and for integrity checks at least. I can't imagine writing without reading. But maybe the graph is set to display only data after a certain amount ? for example I have a software on my MAC that shows network traffic only when superior to 1Kbyte/s to filter out keepalives.