yoy.be "Why-o-Why"

Creating a virtual image of that old laptop

2010-10-28 23:23  i2944  weblog computers  [permalink]

The last few days I've been looking up a lot of information on a specific topic, but haven't found all that I need in a single place, so here it goes. This is the story of (yet another) someone that had the great idea of 'cloning' a virtual image out of the old physical machine, to run as a virtual machine on the brand new machine, with a multiple of the capacity of the old machine.

If you don't care about the story, scroll to the bottom to see the quick guide through the steps to take.

The old, aging, deteriorating laptop is ready for retirement, it's got its power connector re-soldered twice already, two out of three (...) USB ports no longer respond, etc. But, all your data is on it. It's full of tools and software you use and you'd like to use. You're not looking forward to the awkward time ahead using two laptops, re-installing software and tools, moving data around, and optionally finding out you've lost all of those precious personal perferences, settings, profile data...

Virtualization is a buzzword nowadays among the happy few that pull the reins on the server farms, but it's pretty available for home users as well. So why not try to pull a virtual image off of the physical machine and see if it would run on the new machine?

Step 1: Pulling the image.

A straight-forward method for modular desktop machines was to put the old harddisk into another machine as secondary drive and pull an image from it. I'm moving between laptops and I don't feel like dismantling this one (any more)... So I need to pull an image of the currently running system, from the main harddisk partition, and write it over network, since this 20GB is nearly full.

(On a side note, I'm was quite happy this last months to discover cleanmgr http://support.microsoft.com/kb/253597 and especially the 'remove system restore points' option on the second tab! Hundreds or thousands of dead unused kilobytes just sitting there you can get rid of with a mouseclick.)

I found this great tool that does the trick: http://www.chrysocome.net/dd

dd if=\\?\Device\HardDisk0\Partition0 of=\\\temp\oldlaptop.img bs=128k --progress

'Partition0' apparently is the address of the entire disk, underneath any partitioning or locks the system has on the filesystem. Oddly enough it's available to read from, so take care with running other programs while you're pulling the image. Any files written to while the diskdump is writing may end up corrupt.

I've tried a number of block sizes, ranging from 4k to 2M, but 128k is about a good size to keep both the harddisk and the network interface (100Mbps) busy enough so they won't have to wait on eachother too much. Less would make more read operations, and less data packets going out, more would read more at once, but the disk may forget what to do while the data is flushing down the twisted pair.

Start 2: Running the image.

Let's see. I've selected qemu www.qemu.org to run the image, it's light-weight, runs well (and closes well), but I hear good things about VMWare player also. http://www.vmware.com/products/player/

And it boots! It shows a Windows logo for a second... and throws a 'blue screen of death' with an error that states, among other things "STOP 0000007B", and loops into a reboot which repeats.

Thing is, the old machine had an Intel something in it's center, the new one has it of AMD build, could this be causing problems? From what I read on the web it does. But I've also read all kinds of trickery and tool-slinging to alter registry and core files, but they all boil down to disabling the erring drivers, while still keeping the system running enough to get to boot in a new virtual enclosure.

Start 3: Fixing them drivers.

So back to the old machine. I've tried several things, but what I finally did to get it running is checking every little thing in the device manager (with display of hidden devices swicthed on), which showed the brand's name in the description, and 'update' the drivers to the generic make of drivers, which seem to do the trick also. It may take a reboot or two, and some things may re-appear getting plugged to play again, but you just play them down again putting the generic label on it. (Update driver > no, not now > I wont to choose > don't search > select the plain vanilla one)

Then I took a new diskdump, and just to let this old bird fly again, I restarted in safe mode, and selected to restore a restore point from before I started this endeavor.

Start 4: Does it run now?

Does it run now? Looks like it does, the image is holding a system that wasn't shutdown properly (deuh), so it starts a scandisk before it boots, but that's only normal. Any file that was open at the time of the diskdump may get 'corrected', but I warned you. Then the system boots, telling you you need to activate. Just like you would when you replace your motherboard. (Which I kind of did.)

So, in short, this is what you need to do to convert a physical Windows installation into a virtual image: