ReadyNAS Device Compatibility List

An interesting point, but according to Seagate, these drives use 512-byte sectors.

You missed the point - the reference to 4K sectors was to emphasise the difference in architectures between the Sparc based NAS (Duo, NV+) and the x86 NAS (NVX, Pro etc), not to claim that the seagate drives were 4K sector drives. (I have slightly edited that post to try to clarify without changing the original wording)

Apparently you're not familiar with the Seagate ES.2 SN04 issues, originally reported in this thread, documented as fixed in this beta, and still evident in HCL entries with the comment "RAIDiator 4.01+ required if Seagate firmware is SN03 or SN04"

Actually I am, and this illustrates the point

There Netgear refer to an issue that they intended to, and did, resolve. And they went out and communicated this information. Much as they are doing right now to support 4K sector drives. Whether the issue with ES.2 drives was a issue with the NAS or with the drives is irrelevant - Netgear took ownership of the problem and fixed it.

Now consider that the Constellation drives fail testing - why? They are 512 byte sector drives and *should* work. Is it due to "Bad" drives? Or an issue with the NAS? Has to be one of the 2.

If it is an issue with the NAS, maybe Netgear cannot or will not fix it - or don't consider it worth the effort. If Netgear came out and said this would you accept it and ask no more? Probably not as otherwise these last few posts would not exist. So instead Netgear leave the drives off the HCL, let us draw our own conclusions and need make no more effort on their part - just refuse to comment.

If the fault is in the drives - would Netgear publicise that? And risk causing issues between them and Seagate? Or would they instead just leave them off the HCL and again do nothing more except make Seagate aware of the issue for future?

Either way - They only way we will know for sure about this is if Netgear come out and say something. But the time that has elapsed and the lack of comment from Netgear strongly suggests either:

1. They haven't and won't be testing this disks
2. There is an issue with the NV+ that prevents support that Netgear will not/cannot fix (or not worth the effort that would be required)
3. There is an issue with the drives that prevents Netgear supporting them in the NV+

My contention is option 2) or 3) as I suggested in my original post as these drives have been available for a considerable time, when the NV+ was still a focus sell. In fact, given Netgear's willingness to provide 4K sector support on the NV+ and test other 2TB drives, I'd be inclined to think option 2 is most likely with silence being their best policy