Many Western Digital external USB drives over 2 TB (including at least some My Book, My Book Essential, Elements, and Easystore drives) can be configured for either 512 byte logical sectors or 4096 byte logical sectors using the WD Quick Formatter tool. When configured for 4096 byte logical sectors, the USB-to-SATA bridge in the enclosure does a translation between 512 byte logical sectors at the SATA interface to the internal drive and 4096 byte logical sectors at the USB interface to the host computer.
With 512 byte logical sectors, an MBR partition table could only use up to 2 TB of a drive. That's because MBR table entries are 32 bits with a max of 2^32 or 4,294,967,296 sectors. 2^32 sectors x 512 bytes/sector is 2 TB. With 4096 byte logical sectors, an MBR partition cable can use up to 16 TB of a drive. (2^32 sectors x 4096 bytes/sector is 16 TB) Windows XP only supports MBR partition tables, and so 4096 byte logical sectors are the only way to use all of the space on a drive over 2 TB in Windows XP. The newer GPT partition table format supported in Windows Vista and later does not have the 32-bit limitation, and can support disks larger than 2 TB regardless of the sector size.
The WD Quick Formatter tool (version 2.0.0.65 available for download as of this writing) can enable or disable the sector size translation. This version of the tool does not work correctly under Windows XP, so I recommend running the tool in Windows 7 or later. When run in Windows 7, or in later version of Windows but with Windows 7 compatibility mode, the tool will present two configuration options on the "Format your WD external drive" screen:
- XP Compatible: This option configures the drive for 4096 byte logical sectors, and creates an MBR partition table.
- Most Compatible (Vista or later required): This option configures the drive for 512 byte logical sectors, and creates a GPT partition table.
Both options also create a single partition filling the entire drive, and quick format it in NTFS.
If you run the tool in Windows 8 or later without putting it in Windows 7 compatibility mode, the tool will not present a compatibility option on the formatting screen and it will format in the "most compatible" mode (512 byte logical sectors).
WD Quick Formatter 2.0.0.65 doesn't work correctly in Windows XP: it successfully configures 4096 byte logical sectors, but fails to format correctly. Another tool can subsequently be used to partition and format the drive.
WD Quick Formatter 1.2.0.10 works correctly in Windows XP, but is not available for download from Western Digital anymore.
When the target drive is configured for the same logical sector size as the source, you can copy to it using dd and the copy will work without any need to alter the partition table.
I can confirm that these Western Digital external USB drives can be configured for XP compatibility:
Easystore 14 TB (WDBCKA0140HBK)
Easystore 12 TB (WDBCKA0120HBK)
Easystore 8 TB (WDBCKA0080HBK)
My Book Essential 1140, 3 TB (WDBACW0030HBK)
Elements 1021, 3 TB (WDBAAU0030HBK)
Burned an MSDN tech support incident and just got off the phone with the support engineer. He reproduced this problem on a UEFI system with Windows 8.1 installed. It turns out that the -AllCritical qualifier to the wbAdmin command does not work on a UEFI system because Volume Shadow Service (VSS) can not create a shadow copy of the FAT32 EFI partition.
The solution is to explicitly back up the C partition (without the -allCritical option):
wbAdmin start backup -backupTarget:E: -include:C:
You can ignore the warning that "this backup cannot be used to perform a system recovery". Both the Recovery and EFI partitions are restored during the system restore operation. (Makes sense... they were created during the initial system installation, so Windows obviously knows how to create them again.)
Some notes related to this issue:
Note that the "Recovery" partition is a misnomer. That partition is actually the boot partition. In a legacy (non-UEFI) system, the "System reserved" partition serves the same purpose.
To manage the files on the "backup" drive, use the vssadmin command line tool. Specifically:
vssadmin list shadows shows the show copies (i.e. "backups") stored on your backup drive. Note that, while a backup is in progress, the shadow copy is listed as being on the drive being backed up. The backup operation first creates a volume shadow copy on the volume being backed up, and them moves the shadow copy to the backup drive.
vssadmin delete shadows lets you selectively delete old shadow copies from your backup drive.
To restore a partition, attach the backup disk and boot from the Windows 8.1 distribution media. Select "Repair your computer", then "System image recovery". When the restoration process is done, your EFI and Backup partitions are also restored. (Or at least so claims the Microsoft engineer. I have not verified that this is correct.)
Here are some links (courtesy of the Microsoft tech support guy) that may be helpful:
Edit:
I've discovered that System Image Backup is, in fact present in Windows 8.1; bring up Control Panel/File History, and the link is at the bottom left corner of the window. Scott Hanselman has a blog entry on the subject.
Best Answer
You might want to completely wipe and test the disk with special tools from the brand of the hard disk, that will ensure that you will see the right information. If that doesn't help, the hard drive either has a wrong sticker or is providing the wrong information.