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I was recently engaged by a client to look at their backup and disaster recovery process. In this particular case they had a couple of Windows 2003 Servers - one acting as DC & Exchange Server, the other acting as a file and SQL Server. Both were being backed up to tape using a commercial backup program. So far so good. Whilst this is a fairly standard setup, it would still take quite a bit of time to restore a server in the event of a disaster. You would have to re-install the operating system before restoring application data and system state from tape. My first thought in improving matters was to image each server and store the backups off-site. This is a pretty straightforward process and can be done using any number of commercial tools:- Acronis True Image and StorageCraft ShadowProtect being a couple of good examples. For those on a tighter budget you could also consider using ImageX, a free utility from Microsoft that does bare-bones imaging from the command line. Although it's a useful tool you'll need to boot into something like Windows PE for it to work and it doesn't offer any support for a hardware independent restore. With the server images safely tucked away, I turned my attention to testing the restore process - something that isn't always easy in the real world of SMB. After all, who actually keeps servers around just for DR purposes? Luckily the client had an unused HP ML310 available - a much lower spec than their production servers but more than enough to run Windows 2003. Having only one physical machine provided an ideal opportunity to implement a virtualization solution. After enabling hardware support for virtualization in the system BIOS, I had a decision to make:- do I use VMWare's ESXi 3.5 or Microsoft's Hyper-V Server 2008 R2 (Beta) as the host operating system? My initial plan was to go down the ESXi route given my knowledge of Hyper-V is/was fairly slight. As it turned out, the decision was taken out of my hands as ESXi didn't support the SATA RAID controller on the ML310. Hyper-V Server on the other hand installed without any issues. Getting Hyper-V up and running on server core took a little bit of time to configure. One of the main stumbling blocks is that you have to administer the server from another Windows Vista or Server 2008 machine running the Hyper-V Management console. Creating the necessary firewall, policy and account exceptions is a little tricky, especially if the server is setup in a workgroup configuration. Kudos to John Howard at the Microsoft team who has created an excellent tool that configures all the necessary client and server settings. Creating a couple of guest VM's and restoring the images proved to be a pretty trivial exercise. This got me exploring the world of P2V solutions that are out there at the moment. I came across XENConvert (part of the Citrix XENServer virtualization suite) which you can download and use for free. This tool allows you to convert a disk volume to a virtual hard drive (vhd) while Windows itself is running. To get the best results from XENConvert you may need to temporarily stop some services (Exchange & SQL Server for instance). Once converted, I was able to attach the vhd's directly to my Hyper-V guests and boot straight into the Windows 2003 Server OS. After installing Hyper-V Integration Services and re-configuring the network settings everything started to work. Hyper-V rocks! One downside with XENConvert is that it only works with Windows 2003 Server, XP and older operating systems. It can't yet image Vista or Windows 2008 Server machines. However as a solution for virtualizing older machines on a single platform the entirely free combination of XENConvert and Windows Hyper-V Server delivers a powerful and compelling argument. I'll be doing a full DR test of this setup in a few weeks time. I'll be looking at the switch over process in a lot more detail and examining ways of keeping the backup VM's up to date. I'll blog the results, experience and performance of Hyper-V in a future post. Meanwhile I'd love to know how other people are using P2V tools out in the field - are there other/better ways to do this kind of thing...? Are there ways to automate this and keep a VM on warm standby? |
