Hello everyone.

I bought a new and fresh ST4000VN008 to replace a faulty HDD in my NAS Array (RAID5) on a QNAP NAS.
The new HDD was well packed and without signs of damage.
QNAP support hot-swaps, so I've plugged in the new HD to rebuild the array.
The other HDDs have the same capacity (4TB) and also are all Seagate ST4000VN008.
With my surprise, my NAS saw that the array couldn't be rebuilt cause the new HDD had no space.

I've plugged out the new HDD and I started some checks...

First, I've tried to connect it to my iMac through a SATA/USB interface in order to format... with my surprise, Disks Utility said to me that there are 1801,76 GB inside, instead of 4000GB.
Same story with Windows 10...

There's no Unformatted Partition... also I've tried to change it from MBR to GPT without success...

Last, I've tried to make a Low-Level format with your tool with this results:

Device details
Current date and time: 28/04/2022 09:53:22
HDD Low-Level Format Tool 4.40; http://hddguru.com
Device details for [2] ST4000VN 008-2DR166 0000 [1801,76 GB] (3519069872 512-byte sectors)

Details are unavailable for this device. (note that FW version is not shown)

LOW LEVEL FORMAT
27/04/2022 21:22:47 * * * * * WARNING!!! * * * * *
27/04/2022 21:22:47 DURING THE LOW LEVEL FORMAT PROCESS
27/04/2022 21:22:47 ALL DATA WILL BE FULLY and IRREVERSIBLY ERASED!
27/04/2022 21:24:02
27/04/2022 21:24:02 =================================================
27/04/2022 21:24:02 HDD Low Level Format Tool 4.40; http://hddguru.com
27/04/2022 21:24:02 Low level format: [2] ST4000VN 008-2DR166 0000 [1801,76 GB] (3519069872 512-byte sectors)
27/04/2022 21:24:02 Device capacity: 3,519,069,872 sectors
27/04/2022 21:24:02 Locking device...
27/04/2022 21:24:02 Formatting...
27/04/2022 21:24:02 Format Error occurred at offset 0: 5
27/04/2022 21:24:02 Format Error occurred at offset 65,536: 5
27/04/2022 21:24:02 Format Error occurred at offset 131,072: 5
27/04/2022 21:24:02 Format Error occurred at offset 196,608: 5
27/04/2022 21:24:02 Format Error occurred at offset 262,144: 5
27/04/2022 21:24:02 Format Error occurred at offset 327,680: 5
27/04/2022 21:24:02 Format Error occurred at offset 393,216: 5
27/04/2022 21:24:02 Format Error occurred at offset 458,752: 5
27/04/2022 21:24:02 Format Error occurred at offset 524,288: 5
27/04/2022 21:24:02 Format Error occurred at offset 589,824: 5
27/04/2022 21:24:02 Format Error occurred at offset 655,360: 5
27/04/2022 21:24:02 Format Error occurred at offset 720,896: 5
27/04/2022 21:24:02 Format Error occurred at offset 786,432: 5
27/04/2022 21:24:02 Format Error occurred at offset 851,968: 5
27/04/2022 21:24:02 Format Error occurred at offset 917,504: 5
27/04/2022 21:24:02 Format Error occurred at offset 983,040: 5
27/04/2022 21:24:02 Format Error occurred at offset 1,048,576: 5
27/04/2022 21:24:02 Format Error occurred at offset 1,114,112: 5
27/04/2022 21:24:02 Format Error occurred at offset 1,179,648: 5
27/04/2022 21:24:02 Format Error occurred at offset 1,245,184: 5
27/04/2022 21:24:02 Format Error occurred at offset 1,376,256: 5
----Omissis----
27/04/2022 21:24:06 Format Error occurred at offset 184,483,840: 5

....and at the end the capacity is the same (1801,76 GB)

Any suggestions?

Thanks
Claudio

What does CrystalDiskInfo say?

1801 GB is the capacity you would see if there was a 32-bit LBA limit.

4TB - 2TiB = 1801 GB

_________________
A backup a day keeps DR away.

Did you use the same USB dock/enclosure on both ? Have you tried connecting it directly to SATA.

_________________
Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/

Solved...

The problem was my SATA/USB interface... when I connected the HDD to the internal SATA connector, I was able to format the entire disk and now the capacity is right... 4TB.

I've just trowed my SATA/USB interface into the trashcan...

Thank you all...

Claudio