Backing up independent disks and RDMs

VMware vSphere does not provide snapshots of independent disks and Raw Device Mapping (RDM) disks in physical compatibility mode. Therefore, Agent for ESX(i) can back up such disks only when the virtual machine is in the offline state. The following table explains in detail whether Agent for ESX(i) can back up a disk, depending on the state of a virtual machine.


VM disk modes	ESX(i) 3 machine state			ESX(i) 4 machine state
VM disk modes	Online	Suspended	Offline	Online	Suspended	Offline
Basic virtual	+	+	+	+	+	+
Independent persistent	–	–	+	–	–	+
Independent nonpersistent	–	–	+	–	–	+
RDM in physical compatibility mode	–	–	+	–	–	+
RDM in virtual compatibility mode (basic virtual)	+	+	+	+	+	+
RDM in virtual compatibility mode (independent persistent)	–	–	+	–	–	+
RDM in virtual compatibility mode (independent nonpersistent)	–	–	+	–	–	+

During backup, Agent for ESX(i) skips the disks that cannot be backed up and adds warnings to the log. To avoid these warnings, edit your backup plan so that the independent disks and RDMs in physical compatibility mode are not selected for backup.

If you want to always back up these disks, do one of the following:

If, according to your business process, a machine with independent disks or RDMs in physical compatibility mode goes offline regularly, schedule its backup for these hours.
Install Agent for Windows or Agent for Linux in the guest operating system.
An Acronis Backup & Recovery 11 Virtual Edition license assigned to the host enables you to install agents in an unlimited number of the guest systems.

For more information about how to install the agent, see the installation documentation.

After you install the agent and add the machine to the management server, the machine appears under Machines with agents in the All machines with agents group. When creating a backup plan, select the machine here rather than under Virtual machines. Or you can connect the console to the machine directly as to a physical machine.

You might want to use a different backup strategy for the independent disks or RDMs in physical compatibility mode. For example, if these disks contain frequently changing databases, you can back them up more often than the operating system, or use different settings for them. In this case, create a separate backup plan for these disks.