Create a defragmentation scheduled task in Windows Server 2008

Windows Server 2008 introduces a new extension of Group Policy that allows scheduled tasks to be deployed via a Group Policy Object (GPO). In the case of disk defragmentation, you can configure a GPO to run a defragmentation task. We have to borrow the scripting options from the built-in task, specifically the %windir%\system32\defrag.exe command coupled with the -c parameter.

You configure scheduled tasks through GPOs in the Computer Configuration | Preferences | Control Panel Settings | Scheduled Tasks section of the Group Policy editor (Figure A).

Figure A

Once the scheduled task is made via the GPO, it is located in a different area of the Task Scheduler (taskschd.msc) snap-in compared to the built-in task from the default installation. The GPO tasks will appear above the Microsoft folder in the root of the Task Scheduler Library folder (Figure B).

Figure B

Pushing a defrag task out with a GPO, on the one hand, is good because it ensures a consistent configuration deployed quickly; on the other hand, it may be risky to launch a series of tasks that would send a burst of I/O on the storage system. If this mechanism is selected, here are guidelines for deploying GPOs for defrag:

• Go very granular in the organizational unit structure with different schedules to distribute the workload.
• Consider running this on client PCs.
• Be aware of multiple iterations of defragmentation where SANs are in use.
• Consider consolidated effects of virtual machines.

Do you feel that defragmentation tasks should be centrally managed via Group Policy or local on each server? Share your comments in the discussion.