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(computer science)
The tendency of files in disk storage to be divided up into many small areas scattered around the disk.
(cell and molecular biology)
Amitotic division; a type of asexual reproduction.
(mining engineering)
The blasting of coal, ore, or rock into pieces small enough to load, handle, and transport without the need for hand-breaking or secondary blasting.
Disordered behavior and mental processes.




The process, or result, of splitting a large area of free memory (on disk or in main memory) into smaller non-contiguous blocks. This happens after many blocks have been allocated and freed. For example, if there is 3 kilobytes of free space and two 1k blocks are allocated and then the first one (at the lowest address) is freed, then there will be 2k of free space split between the two 1k blocks. The maximum size block that could then be allocated would be 1k, even though there was 2k free. The solution is to "compact" the free space by moving the allocated blocks to one end (and thus the free space to the other).

As modern file systems are used and files are deleted and created, the total free space becomes split into smaller non-contiguous blocks (composed of "clusters" or "sectors" or some other unit of allocation). Eventually new files being created, and old files being extended, cannot be stored each in a single contiguous block but become scattered across the file system. This degrades performance as multiple seek operations are required to access a single fragmented file.

Defragmenting consolidates each existing file and the free space into a continuous group of sectors. Access speed will be improved due to reduced seeking.

The rate of fragmentation depends on the algorithm used to allocate space and the number and position of free sectors. A nearly-full file system will fragment more quickly.

MS-DOS and Microsoft Windows use the simplest algorithm to allocate free clusters and so fragmentation occurs quickly. A disk should be defragmented before fragmentation reaches 10%.

See garbage collection.


(1) See Android fragmentation.

(2) Storing data in non-contiguous areas on disk. As files are updated, new data are stored in available free space, which may not be contiguous. Fragmented files cause extra head movement, slowing disk accesses. A defragger program is used to rewrite and reorder all the files.

(3) In an IP network, breaking a data packet into smaller pieces in order to accommodate the maximum transmission unit of the network. See IP fragmentation.
References in periodicals archive ?
To put it simply, the fragmentation of the European periphery is the other face of the process of Western European integration.
If what was discussed in the previous paragraph is true, then there is no world without fragmentation.
From 1970 on, growth started to go hand in hand with a process of fragmentation, with the result That today, in the developed democracies, sociology is a heterogeneous centrifugal discipline.
Although there appears to be a need for specialization because it promotes diversification, it may lead to greater fragmentation if there are no controls for training preparation or certification.
For example, Oracle use the terminology of data fragmentation to present the data stored in discontinued area of memory.
Developments in Greece accounted for all of the increase in fragmentation
The company added that the fragmentation procedure follows a capsulotomy and uses the femtosecond laser to split the cataractous lens into sections.
While there are certainly problems associated with fragmentation (and as developers we know them all too well), it is wrong to suggest that it is only a downside," the report adds.
The objectives of this study are to provide a framework for forest fragmentation based prioritization (ranking) of administrative forest areas by using both a tightly integrated multiple criteria decision making (thereafter MCDM) and a geographic information system (thereafter GIS) approaches with general decision support input.
The two web-based services were first launched in Europe to provide a view of the state of fragmentation following the introduction of MiFID.
0, is the addition of the breakthrough IntelliWrite fragmentation prevention technology originally introduced with Diskeeper 2010.