A. The Exchange database uses the Extensible Storage Engine (ESE) to store messages in .edb and .stm files and transactions in the transaction log files. Although the process of backing up these files might seem obvious, several Exchange services lock these files, which can prevent you from backing up the file contents. As a result, you can either perform an online backup or an offline backup:
- Online backup--When you install Exchange, it adds a new section called "Microsoft Exchange Server" to the Windows Backup program (i.e., NTBackup) that lists storage groups and databases available for backup. With an online backup, you don't need to stop Exchange and users can continue to use Exchange as normal.
- Offline backup--Although you can perform an offline backup, I (and Microsoft) don't recommend this approach because it requires that you dismount the mailbox and public folder stores from Exchange to back up the files in the database that are no longer locked by Exchange. The primary disadvantage to an offline backup is that it interrupts user service. You should consider this approach only if your backup software doesn't support the Exchange online backup API (however, you'd be better off changing backup software).
To create an online backup, perform the following steps:
- Start NTBackup (go to Start, Programs, Accessories, System Tools, and click Backup).
- Select the Backup tab.
- Expand Microsoft Exchange Server, then select your server and the information store and the storage groups you want to back up, as this figure shows. You can select a particular store within the storage group if you want.
- Enter a backup destination, then click Start Backup.
- The system will prompt you to overwrite or append the backup if the file exists. Select "Replace the data on the media with this backup," then click Start Backup. The amount of time required to perform the backup will depend on your store sizes.
After you create the backup, you should check the Application event log to ensure no warnings or failures exist. You'll see several entries in the log from ntbackup, ESE, and ESE BACKUP that provide details about the steps performed during the backup process, including transaction log file deletions if you performed a full backup.
Discussing the various backup cycles (e.g., the use of full, incremental, and differential backups) is beyond the scope of this FAQ. As a result, you will want to investigate what type of backup to perform. Keep in mind that NTBackup deletes transaction log files only after performing a full backup, so it's important to regularly run a full backup; otherwise, your disk will fill with transaction files.
It's also important to remember that in Windows 2000 and later, Exchange stores some of its information in Active Directory (AD). Therefore, in addition to backing up the Exchange databases, you need to back up the System State on a domain controller (DC), the IIS metabase, Site Replication Service (SRS--if applicable), and certificate services data.