I have an external disk mounted in my Ubuntu 22.04 with read and write permission. It however ran into issue recently. When I tried to boot Virtual Machine from that disk, it return error “NS_ERROR_FAILURE (0X80004005)“. And, when to save VM settings it output “Runtime error opening ‘/path/to/vm-machine.vbox-tmp’ for overwriting: -113 (Write protect error.).”

I was thinking that’s an configuration error in /etc/fstab for auto-mounting disk partition. Until touch command returned “Read-only file system” while ls -al and file ‘Properties’ dialog did say I have both read and write permissions.

After digging around, I found that’s something to do with Microsoft Windows. I have Ubuntu dual boot with Microsoft Windows 10. Both systems are able to access that external disk. And the issue occurs sometime after making changes to that disk from Windows 10. And, the solution is just disable “Fast Startup” in Windows.

Disable Fast Startup in Windows 10

The configuration page varies a bit in different Windows editions. Here’s how to disable the feature in Windows 10.

1. First open “Settings” from start menu. When it opens, click “System” to go power settings page.

2. In next page, navigate to “Power & sleep” in the left pane. Then, click on “Additional power settings”.

3. Then, click the “Choose what the power button do” link in the left in next pop-up dialog.

4. Finally, click “Change settings are currently unavailable” link to unlock settings option, un-check “Turn on fast startup”, and finally save changes.