Highly available cluster agent for backup and restore operations

1. A method for backing up a virtual machine in a cluster, wherein the cluster includes nodes and wherein the virtual machine resides on one of the nodes, the method comprising: registering a cluster agent with a backup server, wherein the cluster agent is a cluster resource of the cluster and wherein the cluster agent has an IP address and name that is independent of IP addresses and names of the nodes and virtual machines in the cluster and wherein the backup server is unaware of which node in the cluster the cluster agent resides on;

receiving a workorder at the cluster agent from the backup server to perform a backup of a virtual machine, wherein the workorder identifies the virtual machine to backed up, wherein a location of the virtual machine or a node on which the virtual machine is operating is unknown to the backup server;

querying the cluster, by the cluster agent to determine the location of the virtual machine;

locating, by the cluster agent, the node in the cluster on which the virtual machine resides based on the workorder, wherein a local agent operates on the node on which the virtual machine resides, wherein the backup server is not required to know any names or addresses of nodes in the cluster, wherein the cluster agent represents the cluster as a single entity to the backup server and wherein the backup server communicates with the cluster agent during a backup operation or with the local agent after a backup operation is initiated;

sending a workorder to the local agent, wherein the workorder is communicated to the local agent by the cluster agent; and performing a backup of the virtual machine.

2. The method of claim 1 , further comprising determining the node in the cluster on which the virtual machine resides when the backup is actually performed such that the backup is performed even when the virtual machine has migrated within the cluster between a time that the backup operation was scheduled and a time that the backup operation was performed.

3. The method of claim 1 , further comprising determining the location of the virtual machine by the cluster agent.

4. The method of claim 1 , wherein performing a backup of the virtual machine includes the cluster agent coordinating with a local agent to perform the backup of the virtual machine, wherein the local agent resides on one of the nodes in the cluster.

5. The method of claim 1 , further comprising performing the backup by generating a save set, wherein configuration information of the virtual machine and of the cluster are included in the save set.

6. The method of claim 1 , further comprising reporting a status of the backup to the backup server.

7. The method of claim 1 , wherein a name of the cluster agent is independent of names of hosts and of names of virtual machines in the cluster.

8. A method for restoring a virtual machine in a cluster that includes nodes, the method comprising:

sending a workorder to restore the virtual machine in the cluster to a cluster agent by a backup server, wherein the backup server is unaware of a location of the virtual machine in the cluster when the workorder is sent, wherein the cluster agent has an IP address independent of the nodes in the cluster such that the cluster agent can be contacted by the backup server regardless of which node the cluster agent resides on, wherein the backup server is unaware of which node in the cluster the cluster agent resides on, wherein the backup server is not required to know any names or addresses of nodes in the cluster, wherein the cluster agent represents the cluster as a single entity to the backup server and wherein the backup server communicates with the cluster agent during a restore operation or with the local agent after a restore operation is initiated;

determining, by the cluster agent, the location of the virtual machine in the cluster in response to the workorder by querying the cluster for the location of the virtual machine to be restored at a time of performing the workorder;

identifying a node in the cluster on which to restore the virtual machine as a destination for the virtual machine; restoring the virtual machine on the node, wherein the virtual machine is restored from a save set stored by the backup server.

9. The method of claim 8 , wherein identifying a node comprises identifying the node on which the virtual machine is instantiated when the virtual machine exists.

10. The method of claim 9 , wherein identifying a node comprises identifying the node on which the cluster agent is instantiated when the virtual machine does not exist in the cluster.

11. The method of claim 8 , further comprising communicating the workorder to a local agent associated with the identified node, wherein the local agent restores the virtual machine and communicates with the backup server to restore the virtual machine.

12. The method of claim 8 , wherein the cluster agent coordinates restores for all virtual machines in the cluster.

13. The method of claim 8 , further comprising adjusting a configuration of the save set prior to restoring the virtual machine to the identified node.

14. The method of claim 8 , wherein the cluster agent is configured to migrate to other nodes in the cluster to ensure high availability of the cluster agent.

15. The method of claim 8 , wherein the cluster agent is configured as a cluster resource and is configured to be contacted by the backup server regardless of which node the cluster agent resides on using the IP address.

16. The method of claim 8 , further comprising restoring the virtual node by the local agent after the restore has been initiated by communication with the cluster agent, wherein the restore is independent of the node on which the virtual machine resides.

17. The method of claim 8 , wherein the node on which the virtual machine is restored is: the node on which the virtual machine is located when the virtual machine exists prior to the restore; the node on which the local agent is instantiated; or the node on which the cluster agent is instantiated.