Mailbox Database is a major component of Exchange 2016. Exchange mailbox database is .edb file that contains data, data definitions, checksums, flags and other information that make up mailboxes. It is the .edb database file where all the mailboxes are stored. Exchange uses Extensible Storage Engine (ESE) as it’s database engine. When emails comes into Exchange server, the email first comes into memory (RAM), then it comes to transaction logs and then the email is stored into exchange database. Transaction log files of a particular database records all the transaction performed on a database. Different set of transaction log files are created for different database. You can create multiple mailbox database which will create multiple .edb files and different set of transaction log files. When you perform clean install of Exchange 2016, a default mailbox database is created automatically in default Exchange installation location of, C:\Program Files\Microsoft\Exchange Server\V15\Mailbox\. Similarly, a set of transaction log files are also created in same directory. It is highly recommended that you create mailbox database in drive other than system drive. When you create mailbox database in Exchange 2016, you also need to specify log folder path.
Create Mailbox Database in Exchange 2016
To create mailbox database in Exchange 2016, log on to Exchange Admin Center (EAC). Click servers on the features pane. Select databases tab.
Click + “Add” button.
Type name of the database. Browse mailbox server where you will store the database. Type location for database and log files. Click save. It is best practice to store database file and logs in different drives. Transaction logs can come handy while recovering Exchange database.
Click OK on the warning.
The database has been created. Now, restart information store.
Open services snap-in. Right-click Microsoft Exchange Information store and click Restart. You can browse the stored location to view database file as shown below. The database file is a single .edb file.
You can also view transaction logs file as shown below.
These transaction log files are very important in backup and restore operation of database. There are many file types shown above each have it’s own functions,
- Transaction Log File (.log): These are the actual transaction log files that stores all the transaction performed on database. Transaction means all the read or write operation performed on the database. All information are stored in logs before writing them to database. This is because if a database error occurs or if database is corrupted then database can be recovered from these transaction logs. The database can be restored from transaction log files if circular logging is not enabled. These are 1 MB in size. The name of files are in hexadecimal. For example, E0100000001 is hexadecimal.
- Checkpoint File (.chk): Checkpoint file keeps track of transactions already written to database. If circular logging is enabled, transaction logs that are already written to database are deleted creating free space on the particular drive.
- Temporary Database (temp.edb): It is temporary database where transactions are processed.
- Exchange Reserve Transaction Log File (.jrs): Reserve transaction log file are placeholders and are used only when the drive runs out of space.
Now you know that lot of heavy work is done in log folder location. So make sure the storage volume for log files is different from database storage location and the storage also have high read/write speed. Make sure volume that hosts transaction logs have free space and avoid using circular logging feature. These transaction logs files can be handy in restoring exchange database. Optionally, you can also configure Database Availability Group (DAG) for database replication and high availability. Perform regular backup of Exchange server with exchange aware backup application. You can now create mailboxes in the new mailbox database.