Diskeeper 10 User's Manual

Answers to Frequently Asked Questions 67
advantage of RAID. In fact, the effects of fragmentation can be more obvious in a RAID array than in a single
disk drive.
Diskeeper defragments RAID arrays just as it does single disk drives. Diskeeper improves the speed and
performance of a RAID environment by eliminating wasteful and unnecessary I/Os from being issued by the
file system. In our four-drive array example, it would defragment the pieces of the file on each separate drive as
though they were separate files, and as directed by the RAID controller.
Why do I get an incorrect excess fragment count after defragmenting an NTFS
drive under Windows 2000?
Under Windows 2000, NTFS files that have been compressed, then decompressed, accumulate excess space
allocations that Diskeeper cannot move. (The defragmentation APIs can only move actual data, not unused
allocated space in the file.)
Microsoft states in knowledge base article Q228198 "Disk Defragmenter Analysis Shows More File Fragments
Than File Size Suggests" that the "excess allocation" is released when the file is closed. Experiments performed
in our labs show that this is not the case. The disk must be dismounted and remounted (or the system rebooted)
followed by an open and a close of the file for the excess allocation to be released.
Therefore, when this condition exists on an NTFS volume, Diskeeper moves the data portion of a file, and if the
file has an excess allocation, it can actually fragment the file—one piece being the data just moved, the other
piece being the excess allocation “left behind”. Diskeeper notes this properly in its statistics. However,
sometime after the file movement is completed and the file is closed, the excess allocation is released by
Windows 2000. Thus, a subsequent analysis shows the fragmentation figures reported at the end of the
defragmentation run to be wildly wrong.
This excess allocation phenomena was introduced in Windows 2000, but is not present in Windows XP or
Windows Server 2003.
Diskeeper engineers are working on a solution for this inconsistency. Until it is found, you can (1) avoid using
NTFS disk compression or (2) perform a subsequent disk analysis to get the correct information.
Does Diskeeper support Windows clustering?
Diskeeper is certified for Windows clustering. To run Diskeeper in a clustered environment, perform the
following steps:
1. On the system that has control of the clustered disk(s), install Diskeeper and schedule it.
2. Fail the clustered disks over to the other system, install Diskeeper and schedule it.
After you perform these steps, Diskeeper will run on the clustered system that remains in operation after the
other clustered system has experienced a system failure. Diskeeper will also run on the clustered disk/partition
in an active-active cluster, defragmenting the clustered disk/partition on the system that currently has control of
the disk/partition.
Note: the Diskeeper Boot-Time Defragmentation will not run on clustered partitions.
How can I run Diskeeper from an account that is not a member of the
Administrators group?
If the account you are using is not a member of the Administrators group, you will not be able to install or
operate Diskeeper. We recommend that you simply use the Set and Forget It feature to set a schedule to allow
Diskeeper to run in the background on all systems. Since the Set It and Forget It operation runs under the
SYSTEM process, there is no need for an administrator to be logged in when it is running.
Do I need to have the Diskeeper service running all the time?
Yes. DkService is the program that actually runs Diskeeper defragmentation jobs. It monitors the Diskeeper
schedule file and starts defragmentation jobs when they are needed. If the Diskeeper service is disabled or not
present, you will not be able to run Diskeeper at all.