4

📢 TL;DR: Bitlocker decryption of a 4TB USB HDD stuck at 82.1% with 0% disc activity for hours. No errors found on the drive, files still fully accessible.

I have been decrypting BitLocker on my USB disc drive for the past two days, and I recently noticed that it had been at "82.1% Completed" for hours. Task manager now shows 0% disc activity for the drive, whereas before it was 100% (for the past two days).

  • Drive: 4TB (USB HDD drive) Bitlocker (full) encrypted, auto-unlock nabled. Recovery key working.
  • Main usage: Backups
  • Unique information on the drive: 1TB of data not backed up anywhere else
  • Windows version: 10 Pro 64-bit 1909
  • Bitlocker version: 2.0
  • USB port: 3.0

What I have tried:

1a. Pausing and resuming BitLocker

1b. Rebooting the machine and trying again

1c. Booting into safe mode and trying again

1d. Booting into recovery mode (X:\ administrator command prompt) and using "manage-bde"

1e. Disabling Secure Boot in the BIOS and trying again

1f. Enabling CSM in the BIOS and trying again

1e. Using "manage-bde" to pause, resume, start encrypting and then start decrypting again (on steps 1b, 1c, and 1d).

1f. Connecting the drive to another Windows 10 Pro 64-bit computer and trying steps 1a and 1e.

1g. Running "chkdsk" in an administrator command prompt, and via the GUI version in drive properties, both said no errors were found.

1h. Attempting to use "repair-bde F: G: -rp [Full recovery password, that has been tested and is working] -Force", however I don't have another drive that is 4TB capacity (the "G" drive is a 32GB USB stick). Output:

Bitlocker Drive Encryption: Repair Tool version 10.0.18362

Copyright (C) 2013 Microsoft Corporation. All rights reserved.

LOG ERROR: 0xc000003d

Needs at least 3815318 MB of free space for repair.

ERROR: Not enough free space on output volume to perform repair.

What I have observed:

  1. 30-60% disc activity on the drive for about a second on steps 1a, 1b, 1c,

  2. 100% disc activity on the drive when using "manage-bde -on F:" (re-encrypting the drive)

  3. 100% disc activity on the drive when using "manage-bde -off F:" (decrypting the drive again) AFTER step 2, but only until (I assume) BitLocker gets to the same place where it was stuck before, as disc activity drops to 0%. This leads me to believe that BitLocker may be getting stuck in a particular place or on a particular file.

I still have full access to the drive and can read/write perfectly fine. Have successfully viewed files, added files and removed files (for testing). I can read/write perfectly fine on both Windows machines I tested on.

I have already contacted an "IT Pro/Admin" from Microsoft Support who guided me with steps 1e and 1f, but BitLocker still appears to not be doing a lot.

I have also looked at the BitLocker event logs, but nothing about errors is displayed, simply status messages such as

BitLocker decryption was started for volume F:.

and

The BitLocker protected volume F: was unlocked. Protector GUID: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} Identification GUID: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}

If you have any ideas or suggestions for fully decrypting the drive, please let me know.

12
  • Are any of the files unencrypted? Windows is wonky sometimes on updating progress, I have seen it report a certain percentage and freeze at that number when the task has actually completed.
    – Moab
    Jun 10, 2020 at 12:00
  • Linux can't read the drive and says it's encrypted so I do believe some files are still encrypted. When I initially encrypted it with Bitlocker over a year ago, I selected the "Encrypt full drive" option. Jun 10, 2020 at 12:04
  • There could be a problem with the usb controller in the enclosure, I would see if you can remove the drive from the enclosure and connect it directly to the motherboard for decryption.
    – Moab
    Jun 10, 2020 at 12:10
  • I'm able to read files, open photos/videos, add files and remove files from the drive. If the usb controller is faulty, why would bitlocker be affected but not those read/write operations? Bitlocker has also worked for two days and got up till 82.1%. Observation 3 also shows that bitlocker works fine with decrypting files until a certain point. Jun 10, 2020 at 12:13
  • I hope you have a backup because it sounds like the HDD has failed.
    – Ramhound
    Jun 10, 2020 at 12:39

0

You must log in to answer this question.

Browse other questions tagged .