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Snapshots provide a fast and space-efficient way to protect SQL Server databases. When using snapshots with SQL Server databases, there are some important considerations to ensure a successful database recovery.
All components of a SQL Server database must be protected as a set. When data and log files are on separate LUNs, these LUNs need to be part of a consistency group. The consistency group will ensure that the snapshot is taken at the exact same time on all LUNs in that group. When data and log files are on multiple SMB file shares, the shares need to reside on the same file system.
When performing a SQL Server database recovery from a block-based snapshot, if the SQL Server instance is to remain online, the Attach to Host action in Unisphere is recommended. For file-based recovery, an additional SMB share is created using the snapshot as the source. Once the volumes are attached, the database can be attached under a different name or used to replace the existing one.
When performing a recovery using the Snapshot Restore method in Unisphere, bring the SQL Server instance offline. SQL Server is unaware of the underlying recovery operations. Taking the instance offline will ensure the volumes are not corrupted by database write activity before recovery. Once the instance is restarted, SQL Server crash recovery will run and bring the databases to a consistent state.