Backup XP Mode?

You are welcome.

Hi Phil, welcome to the Seven Forums.

To start, a short explanation of two vhd's (Virtual Hard Disk) of XP Mode.

The base vhd is the XP core, containing parts that XP Mode needs to run. All user modifications, installed apps etc. are then stored to the second vhd. If these two vhd's are not merged, they are both needed for XP Mode to run. This, using so-called differencing disks, separates XP Mode from all other virtual machines.

To put it short, if you want to distribute an XP Mode virtual machine, you should merge it. It's also the easiest way to let different users (computer or domain) to access the same XP Mode virtual machine. If the XP Mode is differencing (base & personal vhd's), all users have separate XP Mode virtual machines, using the same base. Merging these too vhd's creates a virtual machine which can be used and accessed by different users.

To make it even more complicated, you can then use this merged vhd as a base. A practical and typical example is to install XP Mode normally, install all the software and drivers that are common to all users, merge vhd's and create a new vhd, and using it as a base let users then modify and customize their personal XP Mode's.

I use my system as an example. I have 6 user accounts on my main rigs, on a laptop and desktop. Two of those users use the same XP Mode virtual machine, my personal and work accounts. Both of these accounts are in English, as is the admin account on these two computers. Both computers also have accounts in Finnish, Swedish and German. Maybe a pic of my logon screen tells it better:



For me, it's important that both my accounts, work and private, are able to use the same XP Mode virtual machine, access the same computer in other words. It's also important to me that all other accounts have an individual, separate XP virtual machine.

So, to start I installed XP Mode. I then installed Office, PDF-reader, VLC player and some other stuff that all users need. I merged the differencing disks to a new vhd, and replaced the base vhd with it. I then logged in to each account to install (first boot) XP Mode to those accounts.

Next step was to create a completely new vhd, merging this time the new base with my work account's differencing vhd. Now when I click XP Mode on my two accounts, they open this new vhd which no longer has a base, thus using the same virtual machine. All other accounts use differencing vhd's, the base I created with a personal vhd.

Hope you can understand my rant; I just read through what I've written and have some difficulties to understand it myself

Kari

In one computer / multi user system the merged vhd gives the users a possibility to use one and same XP Mode. If not merged, using a base vhd, each user has an individual XP Mode virtual machine.

I have not noticed any difference in performance.

The merged vhd file can be located wherever the user wants to. Read this tutorial; even if you are not copying your XP Mode, it explains where different XP Mode files are located by default, and what files you have to edit to locate it to a non-default place.

Kari

Theoretically, merged XP Mode vhd is a bit smaller than base & differencing vhd.

The maximum size of a Virtual PC vhd is 127 GB. When a new virtual machine is created, or XP Mode run first time, there are two types of vhd to choose:

• A dynamically expanding vhd takes only as much space on your host hard disk as needed but is automatically expanded when you add data to it. The size of a dynamically expanded vhd is measured and shown in two different ways:
  1. XP Mode > My Computer > Hard disk C: > Properties shows always the maximum size -1GB, 126 GB. The actual space needed can be seen in mow much of this 126 GB is used, in my case space needed is 11.5 GB
     
     
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  2. Host computer > C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines > Xp Mode.vhd > Properties shows another figure, in my case 13.2 GB. This is because a dynamically expanding vhd must be "a little ahead of the time"; it has already reserved almost 2 GB to be ready to expand. This is the real, actual space the XP Mode vhd is taking on my host's HD at the moment
     
     
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• A fixed size vhd. The user can choose the size of the vhd. This size must of course be at least as much as is needed to install the OS in question, in case of the XP some 20 GB would be enough to most users as the size of the HD1. Because it's fixed, it's size is shown correctly both when looking from inside the XP Mode and from host

So, theoretically a differencing XP Mode is base 1.2 GB + 127 GB, when a merged XP Mode is "only" 127 GB.

Dynamically expanding vhd is default. If the user only clicks Next and OK, accepting default choices when installing XP Mode or creating a new virtual machine, it is created using dynamically expanding vhd. Personally, I find no reasons to use fixed size; a dynamically expanding vhd is more practical because its ability to grow or shrink, depending how much data I add or remove.

If you need to free some space in your host's HD, you can try to compact XP Mode (or any other) vhd. Compacting is more effective when using fixed size vhd, a dynamically expanded vhd is already about as small as it can be.

To compact an XP Mode vhd, choose XP Mode > Settings > Hard Disk 1 > Modify > Compact virtual hard disk > Compact:





Hope this answer your question at least partly.

Kari