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Converted disk image doesn't boot (complete freeze).

Posted: 24. May 2022, 19:51
by Bubonis
Host is Win 10 Pro 21H2, VBox is 6.1.34 r150636 (Qt5.6.2).

(Stop me if you've heard this one before...) Have an ancient PC running XP SP3 performing a mission-critical task with no backup. Task is custom written in DOS and cannot be upgraded or replaced because reasons. Before this thing goes up in smoke I want to see if I can get it running in a virtual environment. And here we are.

I pulled the drive from the PC, connected it to my Win10 host, and imaged the old PC's drive to a VDI file using this command:

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VBoxManage convertfromraw \\.\PhysicalDrive2 FrontDeskXP.vdi --format VDI
The conversion was successful, giving me an 11.7GB VDI file.

I created a new VBox machine for XP using all of the default settings + bumping the memory to 2GB, selected my new VDI file as the hard drive, and hit START.

After the VBox splash screen I get the "Windows did not start successfully" screen with "Start Windows normally" selected and the timer happily counting down. When the timer hits zero, or when I hit RETURN to start booting "normally", there's the briefest flash of "hard drive" activity and then the whole VM freezes. My only option is to power down the VM.

Going through the same process but selecting Safe Mode gives me a handful of lines ending with:

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multi(0)disk(0)rdisk(0)partition(1)\WINDOWS\System32\Drivers\Mup.sys
And nothing else. It just stays there forever with no other activity.

I've googled MUP.SYS and the most common fix is to replace the file with one from a known-good XP install. I did that to no positive effect.

Any ideas?

Re: Converted disk image doesn't boot (complete freeze).

Posted: 25. May 2022, 04:01
by scottgus1
You're doing a physical-to-virtual, or P2V, on XP, which has been done a million times. I just did one over the weekend.

XP needs some preparation if the P2V is to work. See How to migrate existing Windows installations to VirtualBox, but only the paragraph "Hard Disk Support" about MergeIDE. (This tutorial is a bit old, and the step-by-step could use a re-write, as there are newer tools available.

Since your XP PC is still running, you can unzip MergeIDE on it and run the MergeIDE.bat batch file. It should make the modifications to loosen the hard drive controller requirements that otherwise cause a '7B' BSOD in XP. Then re-image the hard drive.(You may be able to avoid pulling the drive out and damaging it by running Microsoft Sysinternals' Disk2VHD on the XP PC, save a VHD -not VHDx- to an external drive, and copy the entire XP drive ,all partitions, to the VHD on the external drive. Then use the VHD as the VM's disk.

Also, if your XP was a single-core-processor PC, you might try toggling IO APIC. If it was a 2-or-more-core processor, IO APIC would have been on and needs to stay on.

Please let us know how you get on.

Re: Converted disk image doesn't boot (complete freeze).

Posted: 25. May 2022, 09:53
by mpack
Bubonis wrote:Task is custom written in DOS and cannot be upgraded or replaced because reasons.
I don't think you should be so quick to gloss over those reasons. You don't have to go all the way back to XP just to run DOS apps.

Other options are:
  • All 32-bit Windows versions support the NTVDM module, the same module used by XP to run 16bit apps, including DOS apps. NTVDM may however need to be enabled in Optional Features. Win10 has a 32bit version. Win11 currently does not.
  • You could run FreeDOS on real hardware, say a small form factor PC bought on eBay. This would however meaning losing modern OS features such as USB, but networking is supported by FreeDOS - so a network share would be how I'd get your app into the machine.
  • You can run a purpose made DOS emulator such as DOSBOX or one of its derivates. These can run 16-bit DOS apps even on Win11-64bit.

Re: Converted disk image doesn't boot (complete freeze).

Posted: 25. May 2022, 14:29
by Bubonis
mpack wrote:I don't think you should be so quick to gloss over those reasons. You don't have to go all the way back to XP just to run DOS apps.
About 80% of the reasons are "the owner has been using the system as-is for the past 20+ years and refuses to do anything differently". The technological challenge is comparatively minimal.

Re: Converted disk image doesn't boot (complete freeze).

Posted: 25. May 2022, 14:43
by Bubonis
scottgus1 wrote:Also, if your XP was a single-core-processor PC, you might try toggling IO APIC. If it was a 2-or-more-core processor, IO APIC would have been on and needs to stay on.
This was the solution. :-) Turning on IO APIC got me past the freeze and to the desktop. Thanks!

Re: Converted disk image doesn't boot (complete freeze).

Posted: 25. May 2022, 16:11
by scottgus1
Great! Glad you're up and running.