VMware has obviously revolutionized the concept of Disaster Recovery by introducing Site Recovery Manager earlier this year. SRM takes advantage of a storage array's remote replication capabilities to replicate Virtual Machine data necessary to bring up a Virtual Machine at the DR site without having to create and install a new OS and applications. Currently, Remote Replication configuration needs to be performed at the storage array level. All VMs that need to be part of the DR plan need to be resident on Primary Volumes (P-VOLs) part of a Remote Replication consistency group or pair. SRM simply creates a DR plan, and then makes use of Site Recovery Adapters (Provided by the specific array's Vendor) to replicate the data over to the secondary site. Once replication is complete, SRM can then allow users to perform DR tests without bringing the Production site down and even bring up the DR site if production site does go down. Now this is a very general description of how SRM works. I am not going into the intricate details of SRM's functionality at this time.

So what if one doesn't have SRM, cant use it, cant afford it or the arrays are not supported with SRM currently? Well, the remote replication capabilities of the arrays is already there anyways and these capabilities can be used without SRM. Configuration of the remote replication is performed at the storage array anyways which is just as simple as using Sun StorageTek Common Array Manager Software for the Sun StorageTek 6000 series and via Storage Navigator for the Sun StorageTek 9000 series arrays.

Once RemoteCopy (ST6000 series) or TrueCopy or Universal Replicator (ST9000 series) has been configured and P-VOL <=> S-VOL pairs have been established, it is just a matter of creating VMs using the P-VOLs, syncing the pairs and one will have a DR site ready.

Obviously I make it sound simplistic. It isn't ofcourse and all of the nuances and caveats apply whether SRM is being used or not. Soon, I will post technical specifics on what these nuances and caveats are and configuration best practices to create a successful DR configuration for VMware environments.