Andy’s Techie Blog » Virtualisation

Poor Virtual PC 2007 Performance on a laptop

This has been blogged about elsewhere but I’m trying to get back in the blogging groove and I also want to make note of this somewhere!

When I went to the Manchester SBSC group for my SharePoint as a Helpdesk presentation I mentioned I’d had a problem with the performance of my virtual machines.

It’s been bothering me because it was really really bad, so bad I could barely use the mouse and even though my laptop isn’t exactly a powerhouse it should have been ok running the two VMs I needed for my demo.

So with a visit to the TVP SBSC group impending I decided to have another look and see if there was anything else I could do to eek a bit more performance out of the laptop.

It didn’t take me too long to find an entry on the excellent Virtual PC Guy’s blog.
I followed the instructions and I can report it works great! There was an immediate and noticeable difference when using the Virtual Machine.

The post also says that this can drain your battery faster than normal.

This is actually an understatement – it hammers the battery! I watched the battery meter drain before my eyes!
Virtual SBS 2008 Answer File

I recently got around to setting up a hyper-v system at home so I can experiment with SBS 2008 in the comfort of my own home (it never stops !)

This was a great help when swotting up for my recent SBS exam as I break it as much as I wanted to and use snapshots to go back to working system

One of the helpful parts of the streamlined SBS setup process is the answer file (which you HAVE to use if you want to use the migration process)

The official technet documentation says

If you are performing an unattended installation, connect the removable media (such as a floppy disk or a USB flash drive) that contains your answer files. Depending on the contents of your answer files, you may not see some or any of the following installation screens.

If you are using hyper-v you’ll know there is no USB support and I’ll be honest I can’t remember the last time I laid hands on a floppy disk. Also the only floppy drive I have at home is a USB one!

So what did I do?

Well the notes in the technet says removable media so a CD will work perfectly fine

Once you’ve created a CD with the answer file on it, go into the settings of the virtual machine and add a second virtual DVD drive, one for the SBS installation media and one for your answer file

You can use ISOs or DVDs

I actually used an ISO for the answer file and the DVD in the physical DVD drive as I didn’t have the SBS ISO to hand and it was quicker to create the answer file ISO than the either download the SBS ISO or create one from the DVD!
Virtual PC – Couple of gotcha’s

Everyone knows virtualisation is a hot topic. I love the fact I can have a complete test infrastructure without having to keep lots of kit hanging around (you should she what’s in my loft at home!)

I ran into a couple of hiccups last night which I kicked myself for once I’d realised what the problem was so if your a Virtual PC / Server / Hyper V veteran you’ll think I’m a dumbass but I also want to make a note of this as I’ll probably forget!

I use my Technet subscription in combination with Virtual PC at home (new hard disc on order and then it’ll be hyper-v all the way!) and I like to create setups similar to how are clients are working. This generally means an SBS virtual machine with a client PC (mostly XP) sometimes with a member server or if I’m just learning about some new software (e.g Exchange 2007 or SharePoint ) it’ll just be a single server

Last night I was trying something and needed a couple of Windows 2003 servers (no sbs here) so I created my first server, ran updated updates, etc then shut it down and took a copy of the virtual machine to save me some installation time and then started the first machine up again, made it a domain controller and added a client PC to the domain (all good so far)

I then started up my second server so I could configure it as a member server

I spotted I wasn’t able to ping the other server or the client.

They could ping the second server but not the other way around

I only had a single network card in each of the systems and set them to local only so didn’t have anything weird and wonderful going on

After a bit of head scratching I ran arp –a and that was when the penny dropped

Virtual PC creates a MAC address for the system when you first create it. As I’d copied the original system the servers had identical MAC addresses. While I thought the first server and the client were able to ping the second server they actually weren’t. It was resolving back to the first server!

Thankfully the fix is pretty easy (it’s in the troubleshooting section of the virtual PC help file)

Two or more guest operating systems have the same Media Access Control (MAC) address.

Cause: If you create an image of a host operating system that includes Virtual PC and virtual machines configuration files (.vmc files) and copy that image to another computer, each virtual machine configuration file included in the image contains a MAC address. The MAC address will not be reset automatically when you place the image on a new physical computer. As a result, the virtual machines that are copied onto the new computer will have the same MAC addresses as the virtual machines on the computer that was used to create the image.

Solution: Edit the .vmc file to remove the MAC address. Find the following line:

<ethernet_card_address type="bytes">0003FFxxxxxx</ethernet_card_address>

Remove the number so the line appears as follows:

<ethernet_card_address type="bytes"></ethernet_card_address>

After you remove the number, Virtual PC will create a new MAC address the next time you start the virtual machine.

After I’d done that I was able to ping everything ok so joined the domain and rebooted

That was when I ran into my second problem

When I tried to logon I got the following error

The name or security ID (SID) of the domain specified is inconsistent with the trust information for that domain.

No head scratching here though as the message is self explanatory.

The top of this knowledge base article gives a nice explanation of what my problem was here

During installation of Windows, a machine SID is computed to contain a statistically unique 96-bit number. The machine SID is the prefix of the user account and group account SIDs that are created on the computer. The machine SID is concatenated with the Relative ID (RID) of the account to create the account’s unique identifier.

Similar to the last problem in that I’d caused it by using a duplicated system

But what to do about it?

My initial thoughts were SYSPREP or start from scratch but then I remembered the awesomeness(?) that is sysinternals.com would save my skin again

There is a util on the site called NewSID that does exactly what I was looking for here

There is a big disclaimer on the front page for the utility about Microsoft not supporting images that are prepared using NewSID but this was just a test environment and their warning is generally also talking about disk cloning scenarios

I ran the utility and it even helpfully offered to change the computer name for me as well

I restarted the system, rejoined the domain and was able to carry on!
Server 2008 Virtualisation thoughts

Microsoft this week announced details of packing, licensing, etc for Windows Server 2008

The part that initially passed me by was this, (trimmed down for brevity)

Microsoft Hyper-V Server, a hypervisor-based server virtualization product, complements the Hyper-V technology within Windows Server 2008, allowing customers to consolidate workloads onto a single physical server. The estimated manufacturer’s suggested retail price (MSRP) for Microsoft Hyper-V Server is $28 (U.S.).

$28 dollars!!

It didn’t quite strike me what was happening here until i read James O’Neill’s comment,

“There will be a Hyper-v Server edition (I’m told ‘imagine Server core with no other roles’ …) at $28.”

This is a big deal. Especially for small businesses (if i’m interpreting this right!)

I commented previously how some of our clients could make big savings buying less hardware to run multiple servers. This makes it more attractive as you have one less operating system to buy which brings the cost down even more. Remember the virtual operating systems don’t even have to be Microsoft operating systems!

A server operating system specially meant for running other virtual operating systems is very interesting.

Look forward to reading more about this as the Server 2008 release gets closer