Microsoft and VMware are at odds over some “guidance” the virtualizaton software maker has issued about Exchange and disaster recovery.

At issue is a section in a document published by VMware titled “Microsoft Exchange 2010 on VMware Availability and Recovery Options.” which discusses using Database Availability Groups (DAG) clustering for fast recovery following a disaster.

“Database level high availability can be achieved through the use of database availability groups.,” VMware said.

“In the event of a server host failure, a passive copy of the affected mailbox databases is activated,” it continued. “Client access servers establish MAPI connectivity to the newly active database copy and client connections are reestablished.”

“In the background, VMware HA powers-on the failed virtual machine on another server host, restoring the DAG membership and bringing the newly passive database up to date and ready to take over in case of a failure, or to be manually reactivated as the primary active database,” it said.

“While the use of database availability groups on top of hypervisor based clustering is not a formerly supported configuration, internal VMware tests have shown that the two technologies can co-exist and can be a viable solution to ensure maximum recoverability in the case of a host failure.,” it added. Continue reading Microsoft tangles with VMware over Exchange “guidance”

Virtual servers can benefit an organization’s data crunching needs in many ways. One of them is leveraging their native benefits to broaden the availability and recovery options for Microsoft Exchange 2010 deployments.

Most administrators can cite the benefits of virtual machines by rote:

* They’re portable so Exchange need no longer be bound to a particular piece of hardware. That means design decisions don’t need to be permanent. CPU and memory requirements can be changed with a reconfiguration and reboot. What’s more, new hardware can be be more easily accommodated because the virtual machine containing Exchange can be simply transferred to the new machine.

* They’re hardware independent so planners have greater design flexibility putting together the production as well as the disaster recovery components of a system.

Some virtual machine vendors, like VMware, have included robust availability features into their software. For example, the company’s High Availability product can act as a first line of defense against server failure. If a physical server or any critical component in a server goes down or fails, HA will automatically reboot the Exchange virtual machine on another physical server.

Continue reading Availability and recovery options when running Exchange 2010 in a virtual environment