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Windows Update seems to use Hybrid Shutdown and leave Veracrypt volumes mounted?

Topics: Technical Issues
Mar 18 at 9:07 PM
Edited Mar 18 at 9:16 PM
I strongly believe that Windows Update uses the Hybrid Shutdown / Fast Startup when running Windows Update, even though Fast Startup is disabled. This would cause VeraCrypt volumes to 'remain' mounted on every Windows Update.
If my suspicion is true, it would be a bug in Windows Update IMHO. But I am still raising it here, because I hope I can prevent it with VeraCrypt-settings -- and I think it is good if VeraCrypt is aware of it. (And I hope someone else is technically savvy enough to confirm or deny it?)

Prevention
Is there a way to prevent this?
  • my preference would be to disable Windows Update using the Hybrid Shutdown, but could not find a way yet. Does anybody know?
  • my hope is that the VeraCrypt-preferences for Auto-Dismount when "Entering power saving mode" would work for this case. Does anybody know?
    (Do these VeraCrypt-preferences also apply to "Sleep", because I wouldn't want that?)
  • Would it work to turn off all hibernation(?), e.g. using "powercfg.exe /hibernate off"?
TLDR:

Suspicion
  • I noticed my VeraCrypt volumes were sometimes mounted on Startup, rarely however, so I never managed to find a pattern, and did not feel the urge.
    This week I realized it happened after a reboot caused by Windows Update, but I can't remember if this was the case before.
  • I have searched the internet, and could hardly find any indications or evidence for my believe (yet), except for [this]
    (https://www.reddit.com/r/Surface/comments/4x7n41/psa_disable_fast_startup_to_force_windows_to_load/), assuming "AU" = Windows 10 Anniversary Update:
On my desktop, which has no Fast Startup, after I installed the AU using "update and Restart" every 3D game fails to load. Only after I completely shutdown the PC, and had a cold start is when my graphics driver is responsive again.
Over all, Fast Startup is buggy and should be disable regardless.
  • It might be the case here, but that's _very_speculative
  • I wonder if one might be able to reproduce it by removing an update and trying again?
    However, I myself am very reluctant to 'play around' with my OS, on my 'production' PC.
More

The VeraCrypt-FAQ contains this:
Do I have to dismount VeraCrypt volumes before shutting down or restarting Windows?
No. VeraCrypt automatically dismounts all mounted VeraCrypt volumes on system shutdown/restart.
I think would be nice if the answer would refer to the hybrid shutdown, as mentioned in the Limitations-page.

As mentioned in this issue, I think it would be nice for VeraCrypt to check the Fast-Startup-setting (on installation, and/or when creating an encrypted volume).