Rules for Exchange Server storage groups and databases enforced by the Configuration wizard

When you configure your Exchange Server storage groups and databases for SnapManager, the Configuration wizard creates some rules for databases, transaction logs, SnapInfo directories, for sharing of LUNs or occupation of a SAN boot LUN, and Storage Group system files.

Databases

Databases from different Storage Groups cannot share a single LUN. Also, databases cannot share a single LUN with transaction logs, even if both belong to the same Storage Group.

Note: SnapManager restores all databases on a LUN together. To restore an individual database without restoring the rest of its Storage Group, move the database to a separate LUN.

Note: In a Database Availability Group (DAG) configuration, it you have a drive or LUN existing on all the nodes and this drive is used by a database only on some nodes, then other databases cannot use this drive on other nodes of the DAG.
Transaction logs
Transaction logs from different Storage Groups can share a single LUN.
SnapInfo directory
A SnapInfo directory can have its own LUN, or it can share a LUN with transaction logs if you use NTFS hard links. The SnapInfo directory cannot share the LUN with databases.
SAN boot LUN
You cannot place databases, transaction logs, or a SnapInfo directory on a SAN boot LUN (a LUN configured as a boot device for a SAN host).
Storage Group system files
Storage Group system files must be on a LUN that contains the transaction logs for that Storage Group. If you modify the database or move the transaction logs for a Storage Group, the Configuration wizard automatically moves the Storage Group system files to the same LUN as the transaction logs.

Recommended Exchange Server storage groups and databases configurations
Ensure that you place your Exchange Server storage groups and databases on dedicated volumes, place your LUNs correctly, and use the minimum number of LUNs possible, for fast and successful backup and restore operations.
Exchange Server storage groups and databases configurations to avoid
Before you migrate your Exchange database and transaction logs to LUNs during configuration, ensure that you do not manually store any files or directories on the LUNs that contain databases, SnapInfo directories, or host a mountpoint.
Exchange message tracking in an MSCS configuration
When you use Exchange message tracking in an Microsoft Cluster Services (MSCS) configuration, place the message tracking directory on a shared LUN that does not store a database. If you specify a shared LUN with stored database, SnapManager restores an old copy of the message tracking log during the restore operation.

Parent topic: Database migration considerations

Related concepts

Why SnapManager uses NTFS hard links for transaction log archiving