IBM Tivoli Storage Manager for UNIX and Linux Backup-Archive ...

(hostB), it is serviced by the Storage Agent on hostB. Remember the followingconcepts when deploying this type of configuration:vvThe Storage Agents should have unique names on each host, for example staAon hostA and staB on hostB.The Storage Agents should have the same network address and communicationprotocol, for example, each Storage Agent can be configured to use the TCP/IPloopback address (127.0.0.1) and TCP/IP port 1500.To enable LAN-free data movement in the example used by previous section, addthe following options to each stanza in dsm.sys files that were described inprevious sections. For example, to modify the dsm.sys file for NodeA, the followingLAN-free options are added:Servername clinton_NodeAnodenameNodeAcommmethod tcpip...enablelanfree yeslanfreecommmethod tcpiplanfreetcpport 1500lanfreetcpserveraddress 127.0.0.1Other considerations must be taken into account to correctly manage how tapemounts are used during a failover of an instance of the Backup-Archive Client in aclustered environment. For example, an instance of the Backup-Archive Clientcommunicating with Storage Agent staA on hostA has one or more tapes mountedto satisfy the backup request, and the Backup-Archive client fails over to hostB andstarts communication with Storage Agent staB. How the tapes that were mountedon behalf of Storage Agent staA are managed depends on the configuration of theTSM server. You must consider the following:vvvThe Tivoli Storage Manager Server for Windows and AIX has support that willcorrectly identify that Storage Agent staA is no longer communicating with theTivoli Storage Manager Server and after a short period of time, releases therelevant drives. In order to enable this support, you must ensure that theshared=yes and resetdrives=yes parameters are set for the library on the TivoliStorage Manager Server.Although the Tivoli Storage Manager Server on other platforms does not havethis support for the Library Manager, they can still be used as the target ofLAN-free data movement in a clustered environment. In these cases, using theexample above, the drives will be orphaned and no longer available for use untila Tivoli Storage Manager administrator manually releases them. This might besatisfactory if there are sufficient drives, as it would allow the backup to finishnormally.Note that the Tivoli Storage Manager Backup-Archive Client must havesufficient mount points to handle failover cases which can orphan drives for anyamount of time. This includes not only having physical mount points availablebut also ensuring that there are enough mount points configured to the clientnode. For example, the Tivoli Storage Manager Server maximum number ofmount points parameter maxnummp must be set.For more detailed information and examples on configuration of the Tivoli StorageManager Storage Agents and Servers in a cluster environment refer to IBM TivoliStorage Manager in a Clustered Environment.Chapter 2. Configuring the Tivoli Storage Manager client 75