Container file size larger than volume size

[Thwei]

I have following problem.

I used the expander to increase my container file from 3 TB to 4 TB. I have also unticked the "overwrite with random data" option thinking that the resizing will take few minutes. Continuing in another dialog window interestingly the write speed appeared to be 1024 GB/s, and if I remember correctly was telling me that it writes backup header. The dialog somehow was unresposive but didn't clicked cancel. Checked with task manager that the app was writing data to disk at around 50 MB/s. I left PC with the resizing task to not disturb it during the job. After 30 minutes came back to see results but the screen got black (the monitor didn't get any video signal). Only by the power diode and HDD activity was on. I reseted the PC and after restart seen that container file is indeed exactly 4 TB but mounting it gives me only 3 TB of space. How to fix this problem, so that container file will be not resized but volume size inside it will be? Expander shows warning and doesn't accept 4 TB size anymore and want's me to set larger value for it.

[Adrian Kentleton]

Is the container file formatted NTFS?

[Thwei]

Yes, the container file is located on 8TB disk with one partition formated with NTFS and volume inside container file is also NTFS.

[Mounir IDRASSI]

@thwei: even if we don't write random data during resize operation, the resizing of the file will take long time because it is done by Windows not us and Windows need times to commit physical sectors to the file. This commit operation happens when we try to write the backup hear at the end of the extended file. This is something that is out of control of VeraCrypt.

The fact that the operation was stopped before it finishes means that VeraCrypt Expander was not able to write the backup header not extending the filesystem. Ideally in your case there should be an option in VeraCrypt Expander to make it skip the resizing and go direcly to the following steps in order to resume what was aborted.

I will see if I can implement such option quickly since it should be a matter of adding a checkbox to tell VeraCrypt Expander to skip expanding the file. I will let you know how it goes.

[Thwei]

@idrassi: Thank you for your reply. I thought that expanding of file is done by setting new size and writting data at the very end, not all 1 TB as hopefully I was thinking it would be done by setting the container file attribute as sparse file, so unimportant data would not be written to disk.

[Mounir IDRASSI]

@thwei: I have implement a modification in VeraCrypt Expander in order the case you are in. Now, when it detects this situation, it will allow the user to keep the size unchanged and it will just performs the steps needed to expand the filesystem in order to match the full container file size. The commit is here: https://sourceforge.net/p/veracrypt/code/ci/41887545c1ddbc2e4f9bad9f70b0f279d62eac8e/

You can download a binary of VeraCrypt Expander with this modification at the following temporary link (1 week): https://bin.veracry.pt/?ac034b779fbd4269#8EuXrmMvkpbmusKPjEAw1QUvFSZqQGmrLzvVY9C7CQoW

This binary is signed using the same code signing certficate as the official VeraCrypt binaries.

Just launch it and follow the same steps while keeping the file size unchanged in the UI and the end your file container will be fixed.

Concerning your expectation that file resizing will be quick as a sparse file, this wil be true only if the original file container was created as a sparse file (Dynamic option checked in VeraCrypt Format). Was this the case?

[John]

@idrassi: thank you for your help with this - I've just experienced the same problem (windows 10). Although these posts above are from 2019 and you posted a fix, the fix does not seem to have been adopted in 1.26.7 and the direct link above has of course expired. Apologies if I've misunderstood something, but I'd be grateful for your advice and (I think) ideally another download link please? many thanks,

[Thwei]

Sorry for very late reply. The modified version worked as expected.
Regarding question, no it wasn't the case.
Thank you,
Thwei