Database backup types

With Data Protection for SQL Server, you can use the common interface in the Volume Shadow Copy Service (VSS) framework to create database backups.

VSS backups are at the volume and file-level. Legacy backups are a stream of bytes that Data Protection for SQL Server stores on the Tivoli® Storage Manager server.

You can back up Data Protection for SQL Server data by using the following methods:

Table 1. Data Protection for SQL Server backup types
Data Protection for SQL Server
Full database backup (Legacy and VSS)	With this method, Data Protection for SQL Server backs up an SQL Server database and the portion of the transaction log that is necessary to provide a consistent database state. With this backup type, the copy includes enough information from any associated transaction log to create a backup that is consistent with itself. The portion of the log that is included contains only the transactions that occur from the beginning of the backup until its completion.
Copy-only full backup (Legacy and VSS)	With this method, Data Protection for SQL Server creates data backups that do not affect existing backup and restore processes and can be retained in the longer term. For example, you can use this type to back up a log before an online file restore operation. In this example, the copy-only full backup is used once. After the backup is restored, it is deleted.
Differential backup (only Legacy)	With this method, Data Protection for SQL Server backs up only the data pages in an SQL Server database instance that changed after the last full backup. A portion of the transaction log is also backed up. Differential backup is associated with the last full backup that was run. The last full backup might be completed by Data Protection for SQL Server or another application. For example, if you run a full SQL Server-to-disk backup, and run a differential backup, the differential backup is associated with the SQL Server disk backup. You cannot use differential backup for databases on the secondary replica in Microsoft SQL Server 2012.
Log backup (only Legacy)	With this method, Data Protection for SQL Server backs up only the contents of an SQL Server database transaction log since the last successful log backup. This type of backup is preceded by a full backup or an equivalent type of backup. Log backups normally follow full backups. The portion of the log that is included in full and differential backups is not equivalent to a log backup. Additionally, in full and differential backups, the log is not truncated as it is during a log backup. However, a log backup that follows a full or differential backup includes the same transactions as a full or differential backup. Log backups are not cumulative as are differential; they must be applied against a base backup and in the correct order.
File backup (only Legacy)	With this method, Data Protection for SQL Server backs up only the contents of a specified SQL Server logical file. This type of backup can ease the scheduling conflicts if you must back up large databases. You can back up different sets of files during different scheduled backups. File, group, and set backups must be followed by a log backup, but a full backup is not required.
Group backup (only Legacy)	With this method, Data Protection for SQL Server backs up only the contents of a specified SQL Server file group. You can back up the set of database tables and indexes within a specific group of files. The group is specified as part of the setup within SQL Server when you define the database files. If no group is specified and all the database files are part of the primary group, you cannot partially back up or partially restore the database by using the group.
Set backup (only Legacy)	With this method, Data Protection for SQL Server backs up the contents of specified SQL Server file groups and files as a unit.