Installation and User's Guide - Services and Support

IBM ConfidentialThis option must be specified in the dsm.opt file for all potentiallocaldsmagentnode nodes that could be running the Tivoli Storage ManagerRemote Client Agent Service (DSMAGENT):vssaltstagingdir d:\dird: represents a shared drive that is accessible by all nodes in the cluster. It canalso be a disk that follows the Virtual Exchange Server. \dir represents adirectory located on the shared drive. This option must be specified on all nodesthat are used in the cluster. For example:vssaltstagingdir Q:\TSMVSSv When registering nodes to the Tivoli Storage Manager server specifically for VSSoperations, do not specify the Tivoli Storage Manager USerid=NONE parameter.VSS operations will fail when this parameter is specified.v Make sure to specify the following options in each of the dsm.opt files that areused for the LOCALDSMAGENT, REMOTEDSMAGENT, and OFFLOADmachines:CLUSTERNODE NOCLUSTERDISKSONLY NOCluster limitations for VSSBe aware of these limitations when performing VSS operations in a clusterenvironment:v All servers within the cluster must use the same levels of Tivoli StorageManager, Windows, and other applicable software.v Microsoft KB921181 is required to perform VSS Instant Restore in a clusterenvironment.v Dynamic disks are not supported.v VSS Backups that reside on local VSS shadow volumes can only be restored tothe physical node that created the VSS Backup. For example, if NODE_A of acluster created a VSS Backup and stored it on local shadow volumes, NODE_Bof the cluster cannot restore that particular VSS Backup. NODE_B can onlyrestore VSS Backups stored on the Tivoli Storage Manager server or VSSBackups stored on local shadow volumes that were created by NODE_B. This isdue to a limitation related to VSS cluster support and not to Tivoli StorageManager.v VSS Backups that reside on local VSS shadow volumes may be deleted in theevent of a cluster failover. This means that if NODE_A of a cluster created alocal VSS Backup and afterward, the Exchange Server fails over to NODE_B, if aData Protection for Exchange VSS operation is performed on NODE_B of thecluster, the local VSS Backup created by NODE_A will be deleted. This is causedby the fact that the Microsoft VSS architecture is not cluster aware.v The Tivoli Storage Manager Client Acceptor Daemon (CAD) must be installed oneach cluster node so that it can continue operations in the event of a failover.Make sure the CAD service name is the same on all cluster nodes so that it canbe started by a generic cluster service.v It is recommended that the Local DSMAgent client node be a separate nodefrom your normal backup-archive client, as this CAD service will need to bemade a non cluster option.v The Remote DSMAgent client node does not require you to register a separatenode for each server within the cluster as this server only acts as a secondaryserver.v Use the Microsoft vssadmin and vshadow commands to verify the environment.Chapter 1. Data Protection for Exchange Overview 17