Acronis Backup for Windows Server Essentials - User Guide - Manual (Page 280)

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If the application databases are located on a number of machines, back up all of the machines on the
same schedule. For example, include all of the SQL servers belonging to a SharePoint farm in a
centralized backup plan running on a fixed schedule.
Use Volume Shadow Copy (VSS)
Microsoft Volume Shadow Copy Service (VSS) should be used to ensure consistency of the database
files in the backup. Without VSS, the files would be in a crash-consistent state; that is, after the
recovery, the system would be in the same state as if the power were disconnected at the moment
when backup began. While such backups are good enough for most applications, applications that
use databases may not be able to start from a crash-consistent state.
A VSS provider notifies VSS-aware applications that the backup is about to start. This ensures that all
database transactions are completed by the time Acronis Backup takes the data snapshot. This, in
turn, ensures the consistent state of the databases in the resulting backup.
Acronis Backup can use various VSS providers. For Microsoft products, Microsoft Software Shadow
Copy Provider is the best choice.
Using VSS on a physical machine
On a physical machine, using VSS is configurable. This also applies to a virtual machine that is backed
up from inside the guest OS. You may need to enable using VSS manually if the factory preset was
changed from the default value.
You also need to make sure that VSS writers for the respective application are turned on. In Windows
Small Business Server 2003, the Exchange writer is turned off by default. For instructions on how to
turn it on, see the following Microsoft Knowledge Base article
http://support.microsoft.com/kb/838183/.
To enable using VSS by default in any backup plan created on a machine:
1. Connect the console to the machine.
2. On the top menu, select Options > Default backup and recovery options > Default backup
options > Volume Shadow Copy Service.
3. Click Use Volume Shadow Copy Service.
4. In the Snapshot provider list, click Software - System provider.
When the console is connected to the management server, you can set the same default setting for
all of the registered machines.
Using VSS on a virtual machine
When backing up a virtual machine at a hypervisor level, using VSS is not configurable.
VSS is always used for Hyper-V virtual machines if Hyper-V Integration Services are installed in the
guest system.
VSS is never used for VMware ESX(i) virtual machines. If you want to back up databases in a
consistent state, install Agent for Windows in the guest system and enable the Volume Shadow Copy
Service option as you do on a physical machine.
Truncating transaction logs
Active Directory normally uses circular logging. Logs of other VSS-aware applications (except for
Microsoft SQL Server) can be truncated by using the Enable VSS Full backup option (p. 128). This