HGST Ultrastar He10 10TB 7200 RPM 4Kn SAS 12Gb/s 256MB Cache 3.5-Inch ISE Enterprise Hard Drive - HUH721010AL4200 (0F27402)

The drives work perfectly using an LSI 9361-8i RAID card. I bought 4 of these drives and they are also cooler, faster and quieter compared to WD 4TB enterprise drives that I am still using in RAID. As far as warranty goes, the serials of these drives do not show on HGST website and the reason is that they were designated for an enclosure and not a retail sell, but they arrived individually packed the same way the retail drives are shipped. After calling HGST they confirmed the 5 years manufacturer warranty of these drives, so no worries there. I purchased the drives from Overstock.

I bought two of these drives, to replace 2 defective drives in a 15 drive RAID configuration, while I wait for HGST to ship my replacement drives. My wife and I need our RAID storage array working at all times, and with 2-day amazon Prime, this was the quickest way to ensure our storage would continue to work. Now, these drives work so far, but when I checked both drive serial numbers on the HGST warranty quick check feature at [...], both serial numbers are invalid. Now, for the price of these drives, I really need the full 5 year warranty offered by HGST. Very disappointing, and I will like to return both.