Issue upgrading a vhdx in Hyper-V, then native booting from it.

Not really a request for help - more an observation.


Years ago.

At one time, you could not upgrade an OS e.g. from one Insider version to the next when using a native booting vhdx file.

I had to attach the vhdx file to a Hyper-V VM and upgrade using a virtual machine, then I could reconnect VHDX file as a native booting vhdx file (deleting old boot entry and recreating a new one).

Later (couple of years back)

A year or two back, MS made it possible to upgrade a vhdx file in native boot mode. I could update without Hyper-V or do it in VM (e.g. if I wanted to keep using pc whilst vhdx was upgraded). This was the perfect solution - I could upgrade natively or in a vm.

Now (not sure when this started)
Something has happened and now if I upgrade by VM now, and try to reattach the vhdx file as native booting (recreating boot entry), it falls over and refuses to boot.

I can now only upgrade when natively booting - the vhdx does work in a vm.
However, I no longer have the option to do the upgrade in a vm (if I want to natively boot vhdx) which was useful sometimes.

Ok, this is slightly irritating and not a big deal, but if I forget and do the upgrade in a vm, I shoot myself in the foot, and have to revert to a backup!

Thanks for the info, that's good to know. It just happens that I was planning something that this will impact.

hsehestedt said:

Thanks for the info, that's good to know. It just happens that I was planning something that this will impact.

Click to expand...

Of course, I cannot guarantee this is the same for all users - it might be something specific e.g. some drive related issue.

The key point is to test it yourself, making sure you have a backup copy of the vhdx file if it is critical.

TBH, I tend not to backup my Insider VHDX files anyway, as I can just clone my main OS to a vhdx file and reupgrade to the relevant Insider version if needed. I think it is just a waste of space creating backups of what (for me) are temporary installations anyway.

cereberus said:

Of course, I cannot guarantee this is the same for all users - it might be something specific e.g. some drive related issue.

The key point is to test it yourself, making sure you have a backup copy of the vhdx file if it is critical.

TBH, I tend not to backup my Insider VHDX files anyway, as I can just clone my main OS to a vhdx file and reupgrade to the relevant Insider version if needed. I think it is just a waste of space creating backups of what (for me) are temporary installations anyway.

Click to expand...

Query here -- as you seem the best qualified to answer this stuff.

Assuming a load of vhdx files on a single disk (doesn't matter if external or internal) should the main geometry be efi file large partition containing the vhdx files the thing I'm curious to know is the geometry of the contents for the vhdx files

Should they all contain efi -- windows partitions -- i.e each vhdx file has its own efi file or should they have just a data partition. Are there any advantages / drawbacks or doesn't it matter.

The main disk presumably needs an EFI file and to be GPT (if MBR it can only support 4 primary partitions and while there are get arounds W11 won't normally boot) and one has to be able to install the primary boot loader to display the boot menu and Windows choices. An efi file is just a data file stored not in the computers bios but on the HDD itself. An MBR record is stored on sector 0 of the disk and isn't an acessible "data file" in the classic sense.

Cheers
jimbo

jimbo45 said:

Query here -- as you seem the best qualified to answer this stuff.

Assuming a load of vhdx files on a single disk (doesn't matter if external or internal) should the main geometry be efi file large partition containing the vhdx files the thing I'm curious to know is the geometry of the contents for the vhdx files

Should they all contain efi -- windows partitions -- i.e each vhdx file has its own efi file or should they have just a data partition. Are there any advantages / drawbacks or doesn't it matter.

The main disk presumably needs an EFI file and to be GPT (if MBR it can only support 4 primary partitions and while there are get arounds W11 won't normally boot) and one has to be able to install the primary boot loader to display the boot menu and Windows choices. An efi file is just a data file stored not in the computers bios but on the HDD itself. An MBR record is stored on sector 0 of the disk and isn't an acessible "data file" in the classic sense.

Cheers
jimbo

Click to expand...

You only need an efi partition in the vhdx file if you intend to boot the vhdx in a virtual machine.

The host OS could be legacy bios and the native boot vhds do not use separate partitions unlike multibooting. However, always better to use UEFI.

cereberus said:

You only need an efi partition in the vhdx file if you intend to boot the vhdx in a virtual machine.

The host OS could be legacy bios and the native boot vhds do not use separate partitions unlike multibooting. However, always better to use UEFI.

Click to expand...

Thanks

Cheers
jimbo