Ottawa PC Users' Group (OPCUG)


   Copyright and Usage

   Privacy Policy

   Contact Us


Defragging NT - Software Review

by Chris Taylor

I am a big fan of NT. I like the robustness and security it can provide but there are infuriating shortcomings. A few months ago, I reviewed St. Bernard Software's Open File Manager which overcame one shortcoming - the inability to back up open files under NT. 

NT also lacks tools to deal with disk defragmentation. Again, you must turn to a third-party utility to get the job done. There are a couple of products on the market. The most complete and feature-rich product is Diskeeper 3.0 from Executive Software. For four years they have provided the ability to defragment FAT and NTFS hard disk partitions running under NT. 

What does it do?

Disk fragmentation occurs when parts of a file are stored in non-contiguous areas of the disk. Although it may not seem like a big deal, it is possible for a file to be fragmented into hundreds or even thousands of different regions of the disk. The operating system must perform extra work to read the entire file and it takes extra time for the disk drive heads to locate all the file fragments. A heavily fragmented partition also means that free space is fragmented. When new files are written, chances are this causes further fragmentation. 

Some people have assumed that NTFS, being an advanced file system, is somehow immune to file fragmentation - untrue. In fact, trade magazines have reported that NTFS partitions can become too fragmented to access. 

You can run Diskeeper either in interactive mode or as a service. When run interactively, you can perform an analysis on any partition and see the level of fragmentation. You can view the information graphically; different colours depict fragmented files, contiguous files, the Master File Table (MFT), paging files, directories, system files and free space. The information is also available in text format. In text mode you can also see a list of the filenames of fragmented files; this assistance can help you decide if it is important to defragment the affected files. The graphical display is updated in real time as you perform a defragmentation. By default, Diskeeper runs at normal NT priority: the middle of five possible priority levels. 

When run as a service, Diskeeper runs in "Set and Forget" mode. You first specify a schedule which can be one-time, continuous, or repeated. The latter offers a flexible schedule but it is not the easiest to use. You choose from drop down lists with choices: for example, every 2, 4, 8, 12, 24, 48, or 72 hours. Other lists allow you to choose a range of hours the program is allowed to function within (in one hour increments) and the days it may run. You can also specify the priority level this mode should use, with a default of lowest priority. At the default setting it will give up CPU cycles to most other programs - even screen savers. Once you have configured "Set and Forget" mode, Diskeeper will run according to the schedule, even if nobody is logged onto the system. 

The NT Server version of Diskeeper adds the ability to control all copies of Diskeeper running on your network. You can check fragmentation levels, run the program directly or activate the "Set and Forget" mode. You can easily select multiple computers and set the schedule for all of them in a single step. All this can be done whether or not people are logged onto the system. 

You can create exception lists for files you don't care about defragging: for example, infrequently accessed files or those in the Temp directory. 

Diskeeper makes good use of NT's Application log. You may want to consider expanding the size of the log; after all, it not only logs summary information but also creates a log entry for every defragmented file. 

What won't it do?

Diskeeper will not make the partition look pretty. Files will not be moved to the start of the partition, with all free space left in one chunk at the end; Executive Software has determined that this gains little. They aim to defragment files and ensure that the free space is concentrated in a few large chunks. 

Diskeeper will not defragment all files, particularly on NTFS volumes. If there is less than 25% free space on the partition, you will almost certainly end up with some residual fragmentation. This is due to several factors beyond Diskeeper's control. One example is the effect of space reserved for expansion of the NTFS Master File Table. NT can write files into this disk space. Diskeeper can move files out of this disk space but it can't write to this area; hence it is unavailable for defragging files. 

Diskeeper will not defragment directories under normal operation since NT does not permit directories to be manipulated during normal operation. However, Diskeeper can do directory consolidation during a reboot before NT has taken complete control of the file system. Chkdsk should be run before directory consolidation; this can add considerable time to the boot process. Fortunately, this is not an operation you will need to run frequently. 


Executive Software has a free version called Diskeeper Lite. Its main limitation: it runs only in interactive mode at normal priority level. This defragmenter will be included with NT5. You can download Diskeeper Lite from PUB II (DKLITE_I.ZIP in the Disk Utilities file area) or from Executive Software's Web site ( 

How Did it Work for Me?

I am sorry to say that I could not really notice any performance difference after running Diskeeper. The reasons are two-fold. First, the evaluation machine was the PUB II server: used mostly by others accessing our communications server. Second, since I had been running Diskeeper Light, the disk was not too badly fragmented. Prior to installing the full version, Diskeeper Lite had not run for a month. The result was more than 1,000 fragmented files with a total of over 4,000 fragments. Diskeeper was unable to defragment eight files since only 20% free space remained on the partition. Diskeeper was only able to use 11% of the partition for defragmenting; the remaining 9% was being reserved for expansion of the MFT. Once I moved some files to provide 30% free space on the partition, Diskeeper was able to defragment all files. 

Although I was not able to notice a performance gain from a defragmenter partition, I am sure it really does make a difference. I am a true believer in defragmentation. 

I called Inly systems for a price quote on Diskeeper: $399 for the server version and $84.95 for the workstation version. Quantity discounts are available through Executive Software. 

Breaking news!

As I was finalizing this review, Diskeeper 4.0 was released. The main new feature appears to be the ability to defragment paging files.

Bottom Line:

Diskeeper 3.0 (Proprietary)
Executive Software
$399 (server version)
$84.95 (workstation version)

Originally published: November, 1998

top of page



Archived Reviews





The opinions expressed in these reviews
do not necessarily represent the views of the
Ottawa PC Users' Group or its members.