According to Microsoft, large companies lose between $80,000 and $90,000 (£47,000-£53,000) for every hour of downtime they encounter. These kinds of losses occur regardless of whether your business uses physical or virtual servers however, so a good disaster recovery plan is essential in every situation.
Anecdotally, the recovery of virtual servers is easier than their physical counterparts, so how do you go about building disaster recovery into your Hyper-V strategy?
Focus on file backup
Your Hyper-V installation manifests as a group of files on the hard drive of the host server. Any disaster recovery plan needs to ensure that these files are regularly backed up.
If your virtual servers are configured to use dynamically allocated virtual hard drive space, you will need to try and calculate the expected rate of growth and specify a backup regime that can cope. Ensure that you have adequate disk/tape capacity to cover your backup needs at the time of deployment and further into the future as your data storage needs increase.
Keep accurate records
The file-based nature of virtual servers makes it relatively easy to define which items need to be backed up in your Hyper-V environment. However for the speediest retrieval of data in the event of a disaster, you will need to know how to reconfigure your missing servers.
It is extremely important to keep full records of your virtual server set up so that you can configure a new machine and restore data directly into it. Your records need to include full details of information like processors, virtual RAM, hard drive space and network configurations. As well as keeping records of the configuration at the time of deployment, your server setup document needs to be updated every time a configuration change is made.
Prepare for the worst
Accidents can and do happen. Your hard drive image corrupts, the backup media fails, a virtual machine is deleted in error or the RAID array hosting server data crashes – virtually anything can take your servers out of action.
Obviously a good disaster recovery tries to identify and mitigate these risks up front, but a combination of errors and failures could expose flaws in the regime. At this point you should have the ultimate reserve – a data recovery option to extract ‘lost’ data from hard drives. A tool like Ontrack EasyRecovery Enterprise could help dig you out of a hole if your backup lets you down. Or, alternatively you can speak to a reputable data recovery company.
Don’t let Hyper-V server backup become an afterthought. By planning for disaster early in the deployment process, you will be better able to cope in the event of a problem. What are your tips for Hyper-V backup?