WD3000F9MZ-76NVPL0 and WD3009FYPX-09AAMB0 are listed as compatible drives but I cannot find them anywhere online in Canada.
I have 2x WD3009FYPX-09AAMB0 in my DX4000, and the closest I found online would be the WD3000FYYZ, which is an RE drive. I spoke with a WD rep and I was told that the replacement drive needs to be the exact same model for it to work.
I have a dead FYPX and I need a replacement asap. I need advice on what to buy.
In my experience i was able to put a 3rd drive on my unit, even though it was a 4 TB drive I was able to add the 3rd drive and the unit switched then from a RAID 1 to a RAID 5, the only drawback on my case was that I lost 1TB since the other 2 internal drives were 3TB each.
Here is a link that will help you determine which are the compatible internal drives with your unit:
Indeed this is a major problem: to expand the system or to replace faulty hard disks you are forced to use hard disk units which - according to my experience - are not manufactured or sold anymore by WD since months. I bought two DX4000 with 4 Tb a few months ago and I found two 2Tb expansion units just by chance. For sure they are not sold since months on the WD shop. And identical HD Western Digital units with different MDL only for the last digit do not work. Even if it is not officialy reported the DX4000 is de facto a discontinued product as finding replacement disks is almost impossible.
This is a short story of some weeks spent looking for compatible hard disks for our 2 DX4000 units (2x2Tb):
I bought 2 4Tb WD disks but with a final digit 1 instead of 0 in the MDL (WD4000F9YZ-09N20L1) and they are not recognized by the DX4000 (the standard WD4000F9YZ which you can find everywhere cannot be used on the DX4000!)
I found and bought 2 4Tb WD disks WD4000F9YZ-09N20L0 (i.e. expansion disks!) just to discover that my DX4000 will only see them as 2 Tb disks.
Eventually after lot of internet searches I found on Amazon two 2Tb expansion disks (but I had to force the rebuild from RAID1 to RAID5 using Intel RST RAID driver as the automatic rebuild did not work)
Unless you are luck enough to find a 3Tb (or 4Tb, but will be seen as 3Tb) expansion disk searching on internet (i.e. Amazon, Ebay…) the only solution is to install the Intel RST RAID driver. This way you will have full control on the RAID system and you will also manage to use all type of hard disks. I am pretty sure that replacing your faulty disk with an equivalent WD Enterprise disk will work. The problem I found so far with Intel RST driver are that the LED will remain off and that the fan will always work at full speed. If you will not manage to find the 3Tb (or 4Tb) expansion disk I think this is the only way in order not to completely loose your investment.