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Configure AutoReseed for a database availability group in Exchange Server

  • Article

Use the steps in this article to configure AutoReseed for a database availability group (DAG) in Exchange Server.

Caution

The AutoReseed feature doesn't perform any prerequisite configuration tasks for you. Installing disks correctly, adding spare disks to the system, replacing bad disks, and formatting new disks must be done manually by an administrator.

For more management tasks related to DAGs, see Manage database availability groups.

What do you need to know before you begin?

  • Estimated time to complete this task: 10 minutes.

  • To open the Exchange Management Shell, see Open the Exchange Management Shell.

  • You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Database availability groups" entry in the High availability and site resilience permissions article.

  • A single logical disk/partition per physical disk must be created.

  • The specific database and log folder structure described in the steps below must be used.

  • For information about keyboard shortcuts that apply to the procedures in this article, see Keyboard shortcuts in the Exchange admin center.

Tip

Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server, Exchange Online, or Exchange Online Protection.

Step 1: Configure the root paths for databases and volumes

The first step involves configuring the root directories for the databases (AutoDagDatabasesRootFolderPath) and volumes (AutoDagVolumesRootFolderPath) used by the DAG. The defaults are C:\ExchangeDatabases, and C:\ExchangeVolumes, respectively. You can omit this step if you're using the default paths.

This example illustrates how to configure the root path for the databases.

Set-DatabaseAvailabilityGroup DAG1 -AutoDagDatabasesRootFolderPath "C:\ExchDbs"

This example illustrates how to configure the root path for the storage volumes.

Set-DatabaseAvailabilityGroup DAG1 -AutoDagVolumesRootFolderPath "C:\ExchVols"

How do you know this step worked?

To verify that you've successfully configured the root paths for databases and volumes, run the following command.

Get-DatabaseAvailabilityGroup DAG1 | Format-List *auto*

The output for AutoDagDatabasesRootFolderPath and AutoDagVolumesRootFolderPath should reflect the configured paths.

Step 2: Configure the number of databases per volume

Next, configure the number of databases per volume (AutoDagDatabaseCopiesPerVolume) for the DAG.

This example illustrates how to configure this AutoReseed setting for a DAG configured with 4 databases per volume.

Set-DatabaseAvailabilityGroup DAG1 -AutoDagDatabaseCopiesPerVolume 4

How do you know this step worked?

To verify successful configuration of the number of databases per volume, run the following command.

Get-DatabaseAvailabilityGroup DAG1 | Format-List *auto*

The output for AutoDagDatabaseCopiesPerVolume should reflect the configured value.

Step 3: Create the root directories for databases and volumes

Next, create the directories that correspond to the root directories you configured in Step 1. This example shows how to create the default directories using the command prompt.

md C:\ExchangeDatabases
md C:\ExchangeVolumes

How do you know this step worked?

To verify successful configuration of the root directories for databases and volumes, run the following command.

Dir C:\

The created directories should appear in the output list.

Step 4: Mount the volume folders

For every volume that is used for databases (including spare volumes), use the Windows Disk Management application (diskmgmt.msc) to mount each volume in a mounted folder under C:\ExchangeVolumes. For example, if there are 2 volumes with databases and 1 spare volume, mount the volumes to the following mounted folders:

  • C:\ExchangeVolumes\Volume1

  • C:\ExchangeVolumes\Volume2

  • C:\ExchangeVolumes\Volume3

The names of the mounted folders can be any folder name, as long as the folders are mounted under the root volume's path.

How do you know this step worked?

To verify that you have mounted the volume folders successfully, run the following command.

Dir C:\

The mounted volumes should appear in the output list.

Step 5: Create the database folders

Next, create the database directories under the root path C:\ExchangeDatabases. This example illustrates how to create directories for a storage configuration with 4 databases on each volume.

md c:\ExchangeDatabases\db001

md c:\ExchangeDatabases\db002

md c:\ExchangeDatabases\db003

md c:\ExchangeDatabases\db004

How do you know this step worked?

To verify that you have mounted the database folders successfully, run the following command.

Dir C:\ExchangeDatabases

The created directories should appear in the output list.

Step 6: Create the mount points for the databases

Create the mount points for each database and link the mount point to the correct volume. For example, the mounted folder for db001 should be at C:\ExchangeDatabases\db001. You can use diskmgmt.msc or mountvol.exe to do this. This example illustrates how to mount db001 to C:\ExchangeDatabases\db001 using mountvol.exe.

Mountvol.exe c:\ExchangeDatabases\db001 \\?\Volume (GUID)

How do you know this step worked?

To verify that you've successfully created the mount points for the database, run the following command.

Mountvol.exe C:\ExchangeDatabases\db001 /L

The mounted volume should appear in the mount point list.

Step 7: Create the database directory structure

Next, create two directories underneath the folders you created in Step 5, one for each database and one for each of the database's log stream that will be stored on the same volume. You must use the following format for your directory structure:

C:\<DatabaseFolderName >\ DatabaseName \<DatabaseName >.db

C:\<DatabaseFolderName >\ DatabaseName \<DatabaseName >.log

This example illustrates how to create directories for 4 databases that will be stored on Volume 1:

md c:\ExchangeDatabases\db001\db001.db

md c:\ExchangeDatabases\db001\db001.log

md c:\ExchangeDatabases\db002\db002.db

md c:\ExchangeDatabases\db002\db002.log

md c:\ExchangeDatabases\db003\db003.db

md c:\ExchangeDatabases\db003\db003.log

md c:\ExchangeDatabases\db004\db004.db

md c:\ExchangeDatabases\db004\db004.log

Repeat the preceding commands for databases on every volume.

How do you know this step worked?

To verify that you've successfully created the database directory structure, run the following command.

Dir C:\ExchangeDatabases /s

The created directories should appear in the output list.

Step 8: Create databases

Create databases with log and database paths configured with the appropriate folders. This example illustrates how to create a database that's stored in the newly created directory and mount point structure.

New-MailboxDatabase -Name db001 -Server MBX1 -LogFolderPath C:\ExchangeDatabases\db001\db001.log -EdbFilePath C:\ExchangeDatabases\db001\db001.db\db001.edb

How do you know this step worked?

To verify that you've successfully created databases in the appropriate folder, run the following command.

Get-MailboxDatabase db001 | Format List *path*

Database properties that are returned should indicate that the database file and log files are being stored in the above folders.

How do you know this task worked?

To verify that you've configured AutoReseed for a DAG, do the following:

  1. Run the following command to verify the DAG is configured correctly.

    Get-DatabaseAvailabilityGroup DAG1 | Format-List *auto*

  2. Run the following command to verify the directory structure is configured correctly (below are the default paths; if necessary, substitute the paths for the paths you're using).

    Dir c:\ExchangeDatabases /s

    Dir c:\ExchangeVolumes /s