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The latest versions of Exchange rely heavily on Database Availability Group (DAG)s to ensure high availability of data. They are designed to save Exchange Server and databases from any potential server failure or database corruption.
A DAG can have multiple servers as its members provided that they all have same Exchange Server versions (it means, there can never of two different versions of Exchange server in the same DAG). It can consist up to 16 Exchange Servers which further can host multiple databases. And the Database Availability Group save a server which is a member of the group from any potential catastrophe.
When an Exchange Server is a member of DAG, you can quickly recover it if it fails or gets lost. This is using the switch m:/RecoverServer which accesses the server setup in the Active Directory.
After recovering the configuration settings of the server, the switch reloads the files and services again on the server. It also applies the roles and settings which were loaded from the Server in the Active Directory.
Before starting the recovery process, let’s get some information about the Database Availability Group – what it is and how it saves the database.
To work on DAGs (to add, remove, or change settings), you must have adequate permissions. These permissions are to add, remove, and configure settings for database. Here is a table depicting permissions required for the Database Availability Group:
DAG Permissions |
|
Features | Permissions Required |
Database availability group membership | Organization Management
Database Availability Groups |
Database availability group properties | Organization Management
Database Availability Groups |
Database availability groups | Organization Management
Database Availability Groups |
Database availability networks | Organization Management
Database Availability Groups |
Before using the RecoverServer switch you need to perform various exchange commands using Exchange Management Shell:
The command will retrieve the truncation or replay log of the database copies.
The command will delete any database mailbox copy which is present on the server.
The command will delete the mailbox server files and settings from the respective availability group.
The command will add the Exchange server to the availability group.
After completing the process, you can start working on the Exchange Server and access the data in the database.
So, this was the complete process of recovering a Database Availability Group member Exchange server. It is quite simple and direct method of recovering the server. The method may not work well for severely affected data. So, there is no surety of recovery of data. To get an assurance, you should use Kernel for Exchange Server, Exchange Recovery tool. It reads the Exchange database file directly and brings both corrupt and deleted data back. You also do not need to remember the location of the database as the software searches EDB files from any drive or folder.