VMWare and Disaster Recovery
Disaster recovery has been a hot topic for the past few years. Disaster recovery was thrust into the mainstream media after Katrina hit New Orleans and devastated that part of the country. Many people started thinking about disaster recovery afterward and started to look at the solutions available in the marketplace. Hosted disaster recovery is available, but can be cost prohibitive for someone in the SMB market. Standalone servers in a secondary site can be problematic, as it introduces OS and application issues by running on different hardware. However, if a company has virtualized with VMWare, they are already on the track to a comprehensive disaster recover solution.
One of the most dramatic changes that occurs when a server is virtualized is that the server becomes compartmentalized. Basically, all of the files, configuration information, data, and drivers that make up a server in your enterprise are rolled into just a few files. There is a configuration file that tells the ESX server how much memory, drive space, network cards are in the server. Additionally, there is a “vmdk” file, which acts as the virtual hard drive. All OS, server config, applications and data that would reside on the a physical server’s hard drive is stored here in a single large file. Take into account that virtual servers use “virtual hardware”, which is platform independent and can run on any ESX installation. When your servers can be reduced to just a few files, it opens up several possiblilites. Files can be copied. Files can be backed up. Files can be replicated.
In all practical senses, a virtual machine (VM), has been reduced to simply a few files. Looking at this from a disaster recovery perspective, backing up and recovering a server has been simplified dramatically. Where once you needed to use a backup agent to perform a full backup, copy or clone the data to a second site, and have identical hardware available to restore the files to, you now have reduced the entire process to moving a few files. If you need to restore a VM from these files, any ESX installation will do regardless of if it is a Dell, HP, or IBM server on the back end. You can restore a VM running on an HP blade to ESX installed on a Dell rack-mounted server. The difficult part is copying the VM files from your production environment to the DR site, which really isn’t that challenging.
Technically, how does VMWare integrate into a comprehensive Disaster Recovery/Business Continuity plan? There are several options available, ranging from manual replication to using VMWare’s Site Recovery Manager product to develop the plan within your company’s requirements.
I think that this is enough for now. All I ask is that when you think of Disaster Recovery and Business Continuity, think of incorporating VMWare into your solution.