Diskeeper 10 User's Manual

Diskeeper Operation 53
Windows Application Event Log. If you are running Diskeeper manually and the computer switches to battery
power when this option is enabled, a message is displayed informing you that Diskeeper has stopped running.
Using Power Management on Windows Server 2003
The Diskeeper Power Management option under Windows Server 2003 differs somewhat than on other
platforms. This is due to the VSS Volume Shadowing functionality available in the Windows Server 2003
operating system.
The Windows Volume Shadow Copy Service (VSS) provides the ability to create snapshots, or point-in-time
(PIT) copies, of shares and volumes. These snapshots are images of the data on the disk as it looks at a
particular point in time. By keeping these images of data, you can quickly recover individual files or entire
volumes directly from the disk as they appeared when the snapshot was taken.
Important Note: On volumes with a cluster allocation unit of less than 16 KB, VSS will see file movement
done by the defragmentation process as "changed data" and take a point-in-time snapshot, even though only the
location of the data has changed. Defragmentation on volumes with cluster sizes greater than 16 KB is correctly
recognized by VSS and defragmentation jobs will not cause these unnecessary snapshots. Unnecessary
snapshots will cause the VSS storage area to increases in size, possibly resulting in the deletion of earlier VSS
snapshots. For this reason, Diskeeper gives you options to control the defragmentation process on systems with
VSS enabled.
See Microsoft Knowledge Base Article 312067 Shadow copies may be lost when you defragment a volume
for more information. Diskeeper Corporation concurs with the Microsoft recommendation to use 16 KB or
larger clusters on volumes on which you plan to both defragment and employ VSS.
In addition to the basic option to stop defragmentation when running on battery power (as described above),
you will also see these options when using the Power Management option on Windows Server 2003:
• Defragment even if changes to the volume due to defragmentation are saved by VSS Shadow Copy
Enabling this option can cause the VSS storage area to increase in size, potentially deleting earlier
snapshots.
• Show pop-up message when scheduled defragmentation cannot be started because of VSS Shadow Copy
This option alerts you to cases where the defragmentation process cannot be started due to VSS activity.
Permissions
Note: This option is only available in Diskeeper Professional and Professional Premier editions, and is not
supported on Windows 98/Me or Windows NT 4.0.
Click Diskeeper Configuration Properties in the Diskeeper toolbar or the Configure Diskeeper task
group in the Quick Launch pane, then select the Permissions option to specify whether users with non-
Administrator accounts can access and run Diskeeper.
In keeping with published Microsoft guidelines, by default, Diskeeper only allows users who are members of
the Administrators group to analyze and defragment volumes. This option can be used to override that default.
When this option is enabled, all users can access and run Diskeeper. When it is not enabled, only those users
who are members of the Administrators group can access and run Diskeeper.
Terabyte Volume Engine
Diskeeper Server Enterprise edition includes the Terabyte Volume Engine (TVE), which is a specialized
defragmentation engine for very large NTFS volumes (60 GB or larger in size). The TVE is designed to
efficiently handle volumes containing millions of files. Note that the TVE is only used on NTFS volumes.