Configuring advanced settings

A replication set defines what directories/files are to be protected by Double-Take Availability. By default, Application Manager selects all of the necessary directories/files to protect SQL based on your source server configuration. These include the SQL application data and transaction logs, tempdb files, and SQL error logs. By default, the Application Manager-generated replication set will be named sqldag01_<source server name>_<target server name>.

Note:

The path/folder that contains a database’s FILESTREAM data will automatically be included in the replication set for protection if the database is included for protection. Any steps previously taken to enable FILESTREAM support on the source (for instance, file system or operating system-level changes that were made specifically to support FILESTREAM) must also be applied similarly to the target for consistency. Failure to account for FILESTREAM-specific changes on the target server, or specifically excluding FILESTREAM data files/paths from the replication set, can impact SQL Server’s ability to mount a database with FILESTREAM data when failing over.

You should only modify the replication set rules if there are additional directories/files specific to your configuration that must also be protected with SQL. Modifying the default configuration for replication set rules may affect whether data can be successfully replicated. Do not modify the replication set unless you are very familiar with Double-Take Availability and SQL.

To change the replication set rules:

1. Select the Override Generated Rules checkbox.

Note:

When this box is selected, the Protected Databases control on the Connection tab will be disabled. For more information, see Protected databases.

2. To add a replication set rule, click Add. The Add Repset Rule dialog box will appear.

3. In the Rule Path field, type the directory that you want to protect or exclude.
4. In the Include/Exclude area, select whether to include or exclude the path from the replication set.
5. In the Recursive area, select whether the directory should be recursive (protecting all sub-folders under the directory) or non-recursive (protecting only the files in the directory).
6. Click Add.
7. When you have entered all of your replication set rules, click Close to return to the Advanced configuration tab.

Note:

You will need to manually verify that the rule path is correct since the Application Manager does not validate rule paths.

8. To remove a rule, select one or more rules, then click Remove.

Note:

Removing rules that were automatically added by Application Manager could impact the success of failover. Any changes to rules should be thoroughly tested.

9. To reset the rules to the auto-generated rules and to re-enable the Protected Databases control, remove the selection from the Override Generated Rules checkbox.

Scripts are executed at different points during the failover/failback process to perform the actions necessary to make SQL available on the appropriate server. Scripts perform steps such as starting/stopping services, attaching/detaching databases in database-only protection mode, and modifying DNS entries on the DNS server to point users to the appropriate server.

Editing scripts is an advanced feature. Do not edit scripts unless you fully understand what each command is doing.

Scripts are automatically generated by Application Manager during configuration. The scripts are copied to the Double-Take Availability installation directory on the specified server using the administrative share for that server’s drive.

Script	File name	Description
Failover	post_failover_sql.txt	A post-failover script is executed after the core failover processes have completed on the target server. The primary functions of the post-failover script are to start the services on the target and to modify DNS and Active Directory entries as necessary.
Failback	pre_failback_sql.txt	A pre-failback script is executed before failback processing occurs on the target server. The primary functions of this script are to stop services on the target and to move DNS and Active Directory entries as necessary.
Restore	post_restore_sql.txt	A post-restore script is not executed automatically, though it is provided on the source to perform actions that are generally required after data has been restored from the target to source after a failover/failback. The primary function of this script is to restart services on the source server.

By default, Application Manager generates all the required scripts for you automatically based on your system configuration. You can also edit the scripts to add, modify, or delete specific commands. To edit a script:

1. Click on the button for the script you want to update. The script file will be displayed using your machine’s default editor.
2. Enter your changes.
3. Save the script file.

Any change you make to the script in the editor will be copied to the appropriate server when configuration changes are accepted, thus overwriting any changes that have been made outside the Application Manager.

The scripts can be overwritten by certain operations during setup. For example, any changes to configuration options done in the Application Manager will overwrite previous script changes. If you want to make permanent changes to a script, you must modify the appropriate .txt file within the Application Manager installation directory. If there is more than one client machine that will be configuring failover, the change must be made to all the appropriate .txt files.

Before running Application Manager multiple times (for example, when re-enabling protection after a failover/failback), save a copy of your post-restore and pre-failback batch files. After Application Manager executes, replace the default script file(s) with the customized file(s) that you saved.

Select the items to failover.

1. Select the Server Name checkbox if you want the source name to be added to the target when failover occurs (Default = NOT selected).

Note:

After failing over the server name in a SQL 2008/Windows 2008 workgroup, you can't connect to any SQL instance on the target. Do not failover the server name on SQL 2008/Windows 2008.

2. Select the Shares checkbox if you want the source file shares to be added to the target when failover occurs (Default = NOT selected).
3. Select the Active Directory Hostname (SPNs) checkbox if you want to remove the host SPN (Service Principle Name) automatically from Active Directory for the source and add it to Active Directory for the target during failover (Default = NOT selected).

Note:

If you are using Active Directory, you should enable this option. Otherwise, you may experience problems with failover.

The following options allow you to control what functions Application Manager will perform during configuration. By default, Application Manager performs all of these functions. Individual functions should only be disabled for testing or debugging purposes.

Note:

These options are only available when you launch Application Manager using the command line /sql /advanced option (dtam /sql /advanced).

1. Select the Create Replication Set checkbox to automatically create a replication set that includes all of the necessary directories/files that must be protected for your specific configuration. This should only be disabled if you have customized your replication set and do not want to overwrite it (Default = selected).
2. Select the Create Failover Scripts checkbox to automatically generate the failover/failback scripts and copy them to the appropriate server. This should be disabled only if you have customized your script files and do not want them to be overwritten (Default = selected).
3. Select the Create Connection checkbox to create the connection between the source and target using the automatically-generated replication set. This should only be disabled if you would like to verify the replication set that is created by Application Manager prior to connection (Default = selected).
4. Select the Create Failover Monitor checkbox to create a failover monitor on the target to monitor the source for failure. This monitor will use the failover parameters specified during configuration as well as the script files that have been created (Default = selected).