I do not believe this to be an issue with formatting. Both Linux and Windows (64bit) see it as 2TB drive. However it is supposed to be a 3TB drive. It is in an enclosure, and I am wondering if perhaps the enclosure's controller is unable to support larger than 2TB drives? It is a WD MyBook and is not meant to be taken apart to plug in the drive directly into a PC... so before I rip it apart I thought id ask for advice here. It is a USB3.0 enclosure, I believe by the time USB3.0 came about we have resolved 32bit issues?

sudo fdisk -l /dev/sda1
Disk /dev/sda1: 1.8 TiB, 2000362143744 bytes, 3906957312 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos

Device      Boot      Start        End    Sectors   Size Id Type
/dev/sda1p1      1920221984 3736432267 1816210284   866G 72 unknown
/dev/sda1p2      1936028192 3889681299 1953653108 931.6G 6c unknown
/dev/sda1p3               0          0          0     0B  0 Empty
/dev/sda1p4        27722122   27722568        447 223.5K  0 Empty

Under what circumstances will sda1p3 show up like that with all 0's ?

Drive's internal info states its a 3TB drive:

sudo hdparm -I /dev/sda1


ATA device, with non-removable media
        Model Number:       WDC WD30EZRX-00D8PB0
        Firmware Revision:  80.00A80
        Transport:          Serial, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
        Supported: 9 8 7 6 5
        Likely used: 9
        Logical         max     current
        cylinders       16383   16383
        heads           16      16
        sectors/track   63      63
        CHS current addressable sectors:    16514064
        LBA    user addressable sectors:   268435455
        LBA48  user addressable sectors:  5860533168
        Logical  Sector size:                   512 bytes
        Physical Sector size:                  4096 bytes
        device size with M = 1024*1024:     2861588 MBytes
        device size with M = 1000*1000:     3000592 MBytes (3000 GB)

df -lh
Filesystem      Size  Used Avail Use% Mounted on
/dev/root        59G  6.7G   50G  12% /
devtmpfs        484M     0  484M   0% /dev
tmpfs           489M  8.0K  489M   1% /dev/shm
tmpfs           489M  6.5M  482M   2% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           489M     0  489M   0% /sys/fs/cgroup
/dev/mmcblk0p1   44M   22M   22M  51% /boot
/dev/sda1       1.9T  435G  1.4T  24% /media/ExternalHD
tmpfs            98M     0   98M   0% /run/user/1000

Any ideas?

  • You say it’s a MyBook enclosure. Did you install this hard drive manually or did it come in the enclosure? – Daniel B Mar 11 at 6:16
  • I do not remember at this point. Ive had this hard drive for at least 5 years... I might have installed it in there or it might have come with it. This drive has been sitting in the closet for almost entirety of that time and I want to actually start using it, but before I load it up all the way with data I want to see if I can actually utilize the full 3TB. Have you seen sda1p3 report all 0's like that before? – Duxa Mar 11 at 6:51
  • 1
    There's sure to be an exact model number on the enclosure somewhere. Please add it to your question. – Daniel B Mar 11 at 7:13
  • You are onto something. wdbwlg0020hbk-04, which according to this (and the obvious 20 in P/N) points to 2TB drive support.wdc.com/product.aspx?ID=307&lang=en Now I wonder if there is a way to make a 3TB work with it (maybe a firmware flash to the controller or param change or something) ? – Duxa Mar 11 at 7:20
  • Possible duplicate of 3TB SATA hard drives into an old Linux system – Ramhound Mar 11 at 11:07

As you indicated in your comment, you have a Western Digital Elements Desktop 2 TB (WDBWLG0020HBK) enclosure. That means it may not be compatible with hard drives larger than the one it shipped with.

When looking at the reported vs actual sector count, we can see that it is not a trivial problem with data structures:

3,906,957,312 =   1110 1000 1101 1111 0111 0000 0000 0000
5,860,533,168 = 1 0101 1101 0101 0000 1010 0011 1011 0000

The real value is not simply cut off.

It’s unclear whether the controller is ready for 33 bit addresses. As such, we can’t know whether a firmware update would suffice. Not that you’d get that firmware update.


Use gdisk, it is the command needed for disks using GPT partition tables, which yours probably should be using. Your fdisk command should give an error output.

You should be able to either make a second partition on that 3TB disk to use the space that is now "missing", ie unallocated, or if you insist on a single 3TB partition you will have to make a new GPT partition table.


The disklabel type indicates that your disk is having a MBR partition table instead of GPT. GPT partition type is needed for large disks like yours. See: https://ubuntuforums.org/showthread.php?t=2308964

  • While also a reason, in this case we can see in the second line of the fdisk output that it’s not the reason. – Daniel B Mar 11 at 6:17

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