VSS and legacy backup methods

Full backup method (Legacy and VSS)

Use the full backup method for system databases such as master, model, and msdb because of their typical small size. A full backup can take a long time to run. However, the restore process is the most efficient because only the most recent full backup is restored.

Copy-only full backup method (Legacy and VSS)

Use the copy-only full backup method to periodically create copy-only full backups for long-term retention without affecting existing backup schedules or retention policies that you use for disaster recovery. Copy-only full backups do not affect the transaction logs or the sequence of backups, such as differential backups or full backups.

Full backup plus log backup method (Legacy and VSS)

Use the full backup plus log backup method when the normal backup schedule or network capacity cannot support a full backup.

To minimize the effect on the backup schedule and network traffic during peak times, you can run a periodic full backup, followed by a series of log backups. For example, you can schedule full backups on the weekend and incremental backups during the week. You can run full backups during low usage times and when increased network traffic can be tolerated.

Full backup plus differential backup method (Legacy and VSS)

Use the full backup plus differential backup method if your backup schedule and network capacity can facilitate backing up all transaction logs that accumulate between full backup operations. This strategy requires that only one differential backup plus the last full backup be transferred to complete a restore operation. However, the same amount of data must be transferred in the differential image, as in the series of log backup operations.

Although you can run only VSS full backups, you can apply legacy differential backups to the VSS full backup.

Full backup plus differential plus log backup method (Legacy and VSS)

Use the full backup plus differential plus log backup method to reduce the number of transactions that must be restored and applied. Restore operations are faster as a result.

If, for example, you complete a full legacy or VSS backup weekly, and a differential backup nightly, and a log backup every four hours, the restore processing would include the full backup, a differential backup, and at most five log backups. However, if you only complete a full plus log backup scheme on the same cycle, the restore processing would include a full backup plus up to 41 log backups (six days multiplied by six log backups per day plus up to five backups on the day the full backup is completed).

Although you can run only VSS full backups, you can apply legacy log backups and legacy differential backups to the VSS full backup.

File or group backup method (only Legacy)

Use the file or group backup method when it is impractical to back up an entire database because of the size of the data, or associated time and performance issues.

When a group is created on the SQL Server, database files are identified with that group. The group that is used for the group backup depends on the group to which the database files are defined.

File or group options can save backup and restore processing time when certain tables or indexes have more updates than others and must be backed up more often. It is time-effective to contain such data in their own file group or files, and to back up only those items.

Except for logical log files, you can back up your transaction logs after you back up a data file or file group.

Tivoli Storage Manager backups versus local shadow volumes backups

When you create a policy for your backups, you must choose whether to back up data to Tivoli Storage Manager storage versus VSS disks. Data backups to Tivoli Storage Manager typically takes longer to process than backups to local shadow volumes.

Backing up SQL Server data to Tivoli Storage Manager is necessary when long-term storage is required. For example, saving SQL Server data on tape for archival purposes requires long-term storage. Tivoli Storage Manager backups are also necessary for disaster recovery situations when the disks that are used for local backups are unavailable.

By maintaining multiple backup copies on Tivoli Storage Manager server storage, a point-in-time copy is available if backups on the local shadow volumes become corrupted or deleted.

Local shadow volumes

When you back up data to local shadow volumes, ensure that sufficient local storage space is assigned to the local shadow volumes. Create different sets of policies for backups to both local shadow volumes and to Tivoli Storage Manager server storage. If you use a VSS provider other than the Windows VSS System Provider, follow the backup recommendations of the VSS provider.

Environment and storage resources also impact how many backup versions you can maintain on local shadow volumes for VSS fast restore and VSS instant restore operations, and on Tivoli Storage Manager server for VSS restore operations.

Combined VSS and legacy backups