Installation and User's Guide - Services and Support

IBM ConfidentialLegacy BackupA legacy backup is a specialized API backup that functions with the Exchangeserver storage engine. It is occasionally referred to as the Exchange serverstreaming backup and restore API. This is the type of backup provided byprevious releases of Data Protection for Exchange.The following characteristics are true of Legacy backups:v Full, copy, incremental, differential, and database copy backup types aresupported.v Backup granularity is at the database and storage group level.v Backups are stored on Tivoli Storage Manager server storage.v Backups are managed through Tivoli Storage Manager server policy.v Backups can be performed in a Microsoft Cluster Server (MSCS) or VeritasCluster Server (VCS) environment.v Backups provide Exchange Server database zeroing functionality.v Backups provide Exchange Server database integrity check functionality.v Backup and restore of SRS databases is supported.VSS BackupA VSS Backup uses Microsoft Volume Shadow Copy Service technology to producean online snapshot (point-in-time consistent copy) of Exchange data that can bestored on local shadow volumes or on Tivoli Storage Manager server storage. Bothof these storage destinations require that sufficient space be available for thesnapshot. A VSS Backup means the Exchange server is not in ″backup mode″ foran extended period of time because the length of time to perform the snapshot isusually measured in seconds and not hours. In addition, a VSS Backup allows asnapshot of large amounts of data at one time since the snapshot works at thevolume level.Optionally, VSS Backups can be stored locally on VSS shadow volumes that aredirectly accessible by the Exchange system, as long as sufficient space is availablefor the snapshot. These types of backups are fast because data is not placed intoTivoli Storage Manager server storage. Restoring these backups is also fast becausethe Exchange data is not transferred from Tivoli Storage Manager server storageover the network. VSS Backups are only available on Exchange Server 2003 andWindows Server 2003.When performing VSS Backups and moving data to Tivoli Storage Manager serverstorage, sufficient space on local snapshot volumes is still required to hold thesnapshot. For Exchange data backed up to Tivoli Storage Manager server storage,the Exchange data on the snapshot volume is sent to the Tivoli Storage Managerserver. Once the data transfer to the server is complete, the snapshot volume ismade available for reuse. If you are storing VSS Backups locally and the maximumnumber of local backup versions to be maintained (as specified by the TivoliStorage Manager policy) is reached, the oldest backup version is expired in orderto create the snapshot for the backup to Tivoli Storage Manager server storage. See“How Tivoli Storage Manager server policy affects Data Protection for Exchange”on page 18 for details regarding how Tivoli Storage Manager proceeds in thissituation.For Exchange data backed up to local shadow volumes, the snapshot backupresides on the shadow copy volume.Chapter 1. Data Protection for Exchange Overview 7