Technical information

Getting started
O&O Defrag - 23
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 con-
tiguous 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.
l Initial defragmentation of your system
l Computers with few available resources, as the method does not greatly increase the CPU usage and does not
require much free hard disk space
l Servers with large hard disks (e.g. more than 1 terabyte)
l 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 defrag-
mented 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.
l Maximizes the read access performance on servers
l For regularly defragmenting your volumes
l 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.
l 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.