Dynamic Disk Doesn't Grow Automatically

Discussions about using Windows guests in VirtualBox.
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rothers
Posts: 4
Joined: 19. Feb 2023, 17:17

Dynamic Disk Doesn't Grow Automatically

Post by rothers »

Virtualbox 6.1.42, Win7 64 bit host, Win 10 64 bit guest.

I have a dynamic .vdi disk running Win 10 that was originally created 50 GB virtual size that I have now increased to 100 GB virtual size as it's getting full. The actual size won't grow automatically when attempting to copy files that would take it over the current 44.5 GB, just errors out with a Windows not enough space error.
vdidisk.JPG
vdidisk.JPG (71.35 KiB) Viewed 2706 times
Windows Disk Manager
win10parts.JPG
win10parts.JPG (57.14 KiB) Viewed 2706 times
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Dynamic Disk Doesn't Grow Automatically

Post by mpack »

You forgot to update the partition map when you enlarged the drive. This does not happen automatically, and is not part of enlarging the drive (the only bit that VirtualBox cares about).

You already know how to run disk manager, so use it to enlarge the C: partition. I forget how it's done, I imagine just click and drag the allocated/unallocated boundary.

A dynamic drive will only grow when you write to previously unwritten portions of the drive. Windows cannot write to unpartitioned areas, hence at the moment they may as well not be there.
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Dynamic Disk Doesn't Grow Automatically

Post by scottgus1 »

Also try right-clicking the C partition and look for an "Expand" option.

How to Resize a Drive documents the two-step process.
rothers
Posts: 4
Joined: 19. Feb 2023, 17:17

Re: Dynamic Disk Doesn't Grow Automatically

Post by rothers »

Thanks all, extend using Windows disk manager did the trick. Windows now thinks it has a 99.4 GB C: drive less than 1/2 full but the .vdi is only 46 GB, all makes sense now.
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