O&O Defrag 18 Product manual

O&O Defrag 18 
Standard defragmentation methods

In addition to the three new methods, O&O Defrag continues to offer its five older methods for defragmenting your computer.

  • STEALTH
  • SPACE
  • COMPLETE/Access
  • COMPLETE/Modified
  • COMPLETE/Name

All methods can be used on all drives, including volume sets, stripe sets with and without parity, etc., and are equipped for best possible data security. This is achieved by their working together with the defragmentation routines integrated into Windows, and guarantees that data will not be lost if your computer or network crashes, or if there is a power cut.

Defragmentation methods

Defragmentation methods

Note: Please bear in mind that the older methods can only be selected if zone filing is disabled.

Performance new and old methods of O&O Defrag

Methods optimized for Zone filing Standard methods
Optimize Optimize/
Quick
Optimize/
Complete
Space Stealth Complete-Methods
Defragmentation of files + + + + + + + + + + +
Defragmenting the free space + + + + + + + +
Prevention of further fragmentation + + + + + + +
Results of high-level fragmentation* + + + + + +
Suitability for very large files
(> 4 GB)
+ + + +
Suitability for many files
(> 1 M)
+ + + + + +
Run time of first defragmentation** + + + +
Run time of recurring defragmentation + + + + + + +
Required RAM + + + + + +
CPU Load + + + + + +
+ Very Applicable (with runtime: quick)
+ + Extremely Applicable (with runtime: very quick)

* Our understanding of high-level fragmentation is a poorly maintained drive containing a large number of heavily fragmented files with little free space available.

** The run time of the first defragmentation lasts longer than with the previous version as a result of data being divided into zones.

STEALTH Method

The STEALTH method differs from other methods in that it is much faster and uses much less main memory for the defragmentation.

Algorithm

The STEALTH method is based on our unique STEALTH technology and allows an unprecedented level of defragmentation on computers having a large number of files, little free space or available main memory.

This method defragments all fragmented files and tries to consolidate them in order to optimize available free disk space. Speed and resource usage are the main considerations here, and the method is therefore not quite as thorough as the SPACE and COMPLETE methods.

Recommended Application

The STEALTH method is especially useful for defragmentation on a regular basis.

  • Initial defragmentation of your system
  • Computers with few available resources, as the method does not greatly increase the CPU usage and does not require much free hard disk space
  • Servers with very large hard disks (e.g. more than 4 terabytes)
  • Computers with a very large number of files (more than 3,000,000 files)

SPACE Method

The SPACE methods offer you a great solution for heavy fragmentation. It also allows you to consolidate your data so that the amount of contiguous free space is as large as possible and further fragmentation is prevented.

Algorithm

All fragmented files will be defragmented, and then placed into the free slots in which they fit. This maximizes contiguous free space. This method is very quick and efficient and it does reorganize your volume, but not as thoroughly as the COMPLETE methods.

Recommended Application

The SPACE method is ideal for the first defragmentation run on a system that has never been defragmented, as it requires far less free space than the COMPLETE methods. SPACE can also be used for regular defragmentation runs.

  • Initial defragmentation of your system
  • Computers with few available resources, as the method does not greatly increase the CPU usage and does not require much free hard disk space
  • Servers with large hard disks (e.g. more than 1 terabyte)
  • Computers with a large number of files (more than 100,000 files)

COMPLETE/Access Method

The COMPLETE/Access method defragments your files and reorganizes your file structure. Although this method is slower than the STEALTH and SPACE methods, it guarantees maximum system performance when your files are being read.

Algorithm

Files are sorted according to when they were last accessed. The files that have been accessed the least will be placed at the beginning of the partition and those accessed most frequently are put near the end. Seldom-used files are defragmented and will not need to be moved in future. Frequently-used files are placed at the end of the drive. This strategy means that future defragmentation runs will require the least amount of time, as fewer files need to be checked and defragmented.

Recommended Application

If you want to use the COMPLETE/Modified method for your regular defragmentation runs, you should bear in mind that you only use this method on your drive. Combining various methods (COMPLETE, STEALTH, and SPACE) can result in defragmentation taking much longer, as the file system would need to be reorganized each time.

  • Maximizes the read access performance on servers
  • For regularly defragmenting your volumes
  • On computers that have sufficient resources available when the defragmentation takes place – CPU usage is likely to increase significantly (it is strongly recommended that you use the O&O ActivityMonitor). A larger amount of free disk space is necessary with this method.
  • All kinds of servers and workstations

COMPLETE/Modified Method

The COMPLETE/Modified method defragments your files and also reorganizes your file structure. Although this method is slower than the STEALTH and SPACE methods, it guarantees maximum system performance when your files are being read.

The COMPLETE method is particularly suitable for databases and file servers. It is important to bear in mind that this method requires quite a lot of main memory due to file reorganization. If this is likely to be a serious problem for your system, we recommend you use the STEALTH or SPACE methods.

Algorithm

Files are sorted according to the date on which they were last changed. The files which have not been changed recently are placed at the beginning of the partition and those recently changed are placed at the end. This option is a good one for file or database servers containing files that have never been changed (e.g. system files), but where others, on account of their size or content, are frequently modified. (e.g., database files)

This strategy means that future defragmentation will require the least amount of time, as only a few files need to be checked and defragmented.

Recommended Application

If you want to use the COMPLETE/Modified method for your regular defragmentation runs, you should bear in mind that you only use this method on your drive. Combining various methods (COMPLETE, STEALTH, and SPACE) can result in defragmentation taking much longer, as the file system would need to be reorganized each time.

  • Maximizes the performance for write access on servers
  • For regularly defragmenting your volumes
  • On computers that have sufficient resources available when the defragmentation takes place – CPU usage is likely to increase significantly (it is strongly recommended that you use the O&O ActivityMonitor). A larger amount of free disk space is necessary with this method.

COMPLETE/Name Method

The COMPLETE/Name method defragments your files and also reorganizes your file structure. Although this method is slower than the STEALTH and SPACE methods, it guarantees maximum system performance when your files are being read.

The COMPLETE/Name method is particularly suitable for system drives. It is important to bear in mind that this method requires quite a lot of main memory due to file reorganization. If this is likely to be a serious problem for your system, we recommend you use the STEALTH or SPACE methods.

Algorithm

Files are sorted alphabetically from the beginning to the end of the partition and this leads to quick access to files in a directory. When Windows starts up, many system files will be read in sequence from the WINDOWS and the WINDOWSsystem32 directories (DLLs, system drives, etc.) and the start-up time will therefore be shorter.

This method is particularly recommended for computers on which the files rarely change. This reduces the reorganization time that is needed for every defragmentation.

Recommended Application

Please bear in mind that if you use the COMPLETE/Name method for your regular defragmentation runs, it should be the only one used on the drive. Combining various methods (COMPLETE, STEALTH, and SPACE) can result in defragmentation taking much longer, as the file system would need to be reorganized each time.

  • Maximizes the performance for the read access to workstations
  • For regularly defragmenting your volumes
  • On computers that have sufficient resources available when the defragmentation takes place – CPU usage is likely to increase significantly (it is strongly recommended that you use the O&O ActivityMonitor). A larger amount of free disk space is necessary with this method.
  • All kinds of servers and workstations