WinNTSetup v5.4.1

[JFX]

You create a diff.vhd and use this for everything (mounting or booting via BCD).
If you make any changes to the base.vhd the diff will be invalid.

[click-click]

When I create a diff vhd, does Winntsetup update the BCD to use the diff vhd or does this need to be done manually?

[JFX]

No, you have to do this manually.

[click-click]

From what I've read and what you said, if I merge the diff to the base, the diff is no longer usable. I tested this with diskpart, but it did not delete the diff after the merge so I guess this needs to be done manually too. I would like to automate creating a diff, changing the BCD to boot that file  and merging the vhd later when needed. How would I change the BCD from the command line to use the diff ?

 

 

Edited September 5, 2023 by click-click

[JFX]

Yes, that would require to do all steps manually.

Update BCD with bcdedit.exe:

Get the %GUID% form

bcdedit -store S:\EFI\Microsoft\Boot\BCD

than update device and osdevice:

bcdedit -store S:\EFI\Microsoft\Boot\BCD -set %GUID% device vhd=[C:]\diff.vhd
bcdedit -store S:\EFI\Microsoft\Boot\BCD -set %GUID% osdevice vhd=[C:]\diff.vhd

 

Edited September 5, 2023 by JFX

[click-click]

I'm using MBR for my VHDs and I'm not sure where to get the %GUID% from. This is what I ended up with, but still missing GUID.

Is that the value that shows up in the mountvol cmd: \\?\Volume{32034eb7-3cd4-11ee-825d-806e6f6e6963}\    Q:\ or do i need to use something else like the OS GUID (Windows Boot Loader id)?

bcdedit -store Q:\Boot\BCD
bcdedit -store Q:\Boot\BCD -set ????? device vhd=[C:]\W0_ltsb_1607_Diff.vhdx
bcdedit -store Q:\Boot\BCD -set ????? osdevice vhd=[C:]\W0_ltsb_1607_Diff.vhdx

Edited September 6, 2023 by click-click

[JFX]

"bcdedit -store Q:\Boot\BCD" should print something like this:

Quote

Windows-Startladeprogramm
-------------------------
Bezeichner              {1445ab79-433b-4e96-82ee-3b86552f7a64}
device                  vhd=[E:]\Win10H2.vhd
path                    \Windows\system32\winload.efi
description             Windows 10 (VHD)

 

Edited September 6, 2023 by JFX

[click-click]

I get this and resumeobject seems to be the logical choice for the GUID to use, correct?

Also, is the 1st -store even needed to update the BCD or was this just to see  the current setting for the GUID?

c:\>bcdedit -store Q:\Boot\BCD
	Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=Q:
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
default                 {default}
resumeobject            {538b59d5-41e7-11ee-a7ec-c85b76503892}
displayorder            {default}
toolsdisplayorder       {memdiag}
timeout                 30
	Windows Boot Loader
-------------------
identifier              {default}
device                  vhd=[Q:]\W0_ltsb_1607.vhdx
path                    \Windows\system32\winload.exe
description             Windows 10 Enterprise 2016 LTSB (VHDX)
locale                  en-US
inherit                 {bootloadersettings}
recoverysequence        {ee407104-4233-11ee-a481-fb52bd7f26e4}
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
osdevice                vhd=[Q:]\W0_ltsb_1607.vhdx
systemroot              \Windows
resumeobject            {538b59d5-41e7-11ee-a7ec-c85b76503892}
nx                      OptIn
bootmenupolicy          Standard

Edited September 6, 2023 by click-click

[JFX]

No, but {default} is the correct one.

"bcdedit -v -store Q:\Boot\BCD" would show the correct GUID, but you can use symbols like {default} or {current}, too.

Edited September 6, 2023 by JFX

[click-click]

Sorry for being such a pain. The BCD I ended up with to boot the diff had an error.

There is an invalid object in the Boot Configuration Data store Error 0xC0000000f

 

c:\>bcdedit.exe -store Q:\boot\bcd

				
			Windows Boot Manager
		--------------------
		identifier              {bootmgr}
		device                  partition=Q:
		description             Windows Boot Manager
		locale                  en-US
		inherit                 {globalsettings}
		default                 {default}
		resumeobject            {538b59d5-41e7-11ee-a7ec-c85b76503892}
		displayorder            {default}
		toolsdisplayorder       {memdiag}
		timeout                 30				
			Windows Boot Loader
		-------------------
		identifier              {default}
		device                  vhd=[C:]\W0_ltsb_1607_Diff.vhdx
		path                    \Windows\system32\winload.exe
		description             Windows 10 Enterprise 2016 LTSB (VHDX)
		locale                  en-US
		inherit                 {bootloadersettings}
		recoverysequence        {ee407104-4233-11ee-a481-fb52bd7f26e4}
		recoveryenabled         Yes
		allowedinmemorysettings 0x15000075
		osdevice                vhd=[C:]\W0_ltsb_1607_Diff.vhdx
		systemroot              \Windows
		resumeobject            {538b59d5-41e7-11ee-a7ec-c85b76503892}
		nx                      OptIn
		bootmenupolicy          Standard 

c:\>

 

 

 

Edited September 6, 2023 by click-click

[JFX]

Maybe, differencing VHDs are not the best choice for you 

Have not seen that 0xC0000000f error. Could be a problem coming from Bootice edit.

[click-click]

I did not edit from Bootice. I will try starting over from scratch later. Does a diff vhd boot for you like we discussed?

[JFX]

Yes, it working for me, using it from time to time. But the grow rate is quite high.
Just booted a diff and shutdown after 3 minutes it grow  to 1.42 GB.

You could simplify this without editing BCD.
Just rename the VHD to let's say Base.vhd and create a diff with the old name.

Also make sure that parent and diff vhd are in the some folder.

[Antonino]

that is 

On 9/9/2023 at 11:46 AM, JFX said:

Yes, it working for me, using it from time to time. But the grow rate is quite high.
Just booted a diff and shutdown after 3 minutes it grow  to 1.42 GB.

You could simplify this without editing BCD.
Just rename the VHD to let's say Base.vhd and create a diff with the old name.

Also make sure that parent and diff vhd are in the some folder.

that is exactly what I meant at the outset - is there any point in differencing at all? talking of less than 2gigs?

[click-click]

OK,  I wasn't aware that the growth rate would be that high. No sense in pursuing this further. I need to find a better way of getting a reasonable  file diff  of the  VHD.  A full backup of a big VHD each time doesn't seem to be  the way either. Any recommendations how to best backup VHDs or is everyone just using them as throw-away systems without doing backups for them?