The following backup types are supported: Full, Copy, Non-VDI, and Crash-Consistent.
- Full: Protects the database and the active part of the transaction log. This copy type is used when the copy is considered a backup of the database. It is also used when a copy is mounted, to be used as a third-party product to create a backup of the database. It allows restoring of transaction logs to bring the database forward to a time newer than the copy, assuming those transaction logs have a backup. AppSync uses the Microsoft SQL Server VDI snapshot feature to create this type of copy. Full backup type is not supported for Secondary databases in SQL Always On Availability Group (AAG) environment.
Note: Since Full backup type changes the transaction log sequence, it is necessary that you have only one service plan creating full copies of a SQL database. No other third-party backup applications should create “full” copies of the same SQL database.
- Copy: Protects the database and the active part of the transaction log without affecting the sequence of backup. It helps DBAs create a copy without interfering with third-party backup applications that may create full or differential backups of the SQL Server databases or both. AppSync uses the VDI snapshot feature of Microsoft SQL Server to create this type of copy, similar to Full. Copy backup type is supported for secondary databases in AAG environment.
- Non-VDI: Creates crash-consistent copies of SQL using only the Microsoft VSS freeze or thaw framework against the file system without using the VDI snapshot feature of Microsoft SQL Server.
- Crash-Consistent: Protects the database without any agent involvement. Both Microsoft VSS Framework and Microsoft VDI snapshot features are not used. This backup type creates true crash-consistent copies of the SQL databases using array-level features only. Storage array level pre-requisites that are listed below are required for successfully creating crash-consistent copies of SQL databases:
- If SQL databases are hosted on XtremIO, PowerMax, RecoverPoint, VPLEX with XtremIO and SC Series arrays, there are no restrictions.
- If SQL databases are hosted on PowerStore, PowerFlex, VNX, VNXe, Dell EMC Unity, and VPLEX with Dell EMC Unity, all underlying LUNs must be in a consistency group and must belong to the same consistency group.