So at present the HCL only lists the Hitachi 7k4000 HUS724040ALE640 as compatible.
Now this is the Ultrastar device (HUS) and retails at around £250 a disk? The Ultrastar range is offered with a 5 year warranty and 2.0 million hours MTBF. The HCL only indicates the Warranty as 3 years. So are they referring to the Deskstar product HDS724040ALE640 which is offered with a 3 year warranty and retails at around £182 (I can actually get in Ireland for €183 incl VAT)?
So what is the difference between the UltraStar and DeskStar 7K4000 disks - is it just the 2.0 million hours MTBF for Enterprise level usage? Now sure I need the disks warranted for 228.3 year's use.
It sounds like WD Red 4TB have issues. I currently have a pair of 6 month old 2TB WD Red in my Duo (at 83% capacity), that are working fine, and an old (~5 years) pair of 1TB WD Blacks now in USB enclosures connected to an old NSLU2 as backup NAS (at 89% capacity each)
Is there a better 4TB disk for the Ultra 2+? I have bought this NAS 2nd hand, with a 2GB memory upgrade, so there is no Warranty issues to consider.
WDC now provides a supported tool for changing the head parking thresholds on the newer WDC Reds. With that tool, it is probably ok to use them also.
The Seagate drives are a little newer, and have slightly better specs.
Be careful on mix/match with the Seagates though. I think some of the drives in their NAS lines have a slightly lowered number of sectors from usual. The sizes need to match exactly to get mix and match. I recall a posting in this forum on that subject, you might search for it.
Thanks for the pointers - looking at the Seagate NAS 4TB disks, which are currently on Amazon.co.uk for £133.90 each. Will be buying a pair together, so no mix/match issues. Heh - why doesn't the HDD manufacturers etc. provide pairs, 4 & 6 'matched sets' from the same manufacturing run with sequential SNs, for NAS usage?
Also ordered a Fractal 'Silent Series' 92mm Fan to replace the OEM item (Delta afb0912hh), which has a rated noise of 38 dB-A (max 41) whereas the Fractal (FD-FAN-SSR2-92) is rated at 12.5 dB-A I replaced the OEM in my Duo with a 60mm Fractal one and the drop in operating noise was significant, though being much smaller was probably having to work much harder than the 92mm in the Ultra Plus.
It's probably better to get drives from different manufacturing batches; that is, buy them from different resellers and at different times.
This way you potentially avoid getting a set of drives that all have a similar flaw that manifests itself later in a number of drives at the same time.
