Data cluster

Data cluster

In computer file systems, a cluster (sometimes also called allocation unit or block) is a unit of disk space allocation for files and directories. To reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sectors by default, but contiguous groups of sectors, called clusters. On a disk that uses 512-byte sectors, a 512-byte cluster contains one sector, whereas a 4-kibibyte (KiB) cluster contains eight sectors. The term cluster was changed to allocation unit in DOS 4.0. However the term cluster is still widely used.

Comment
enIn computer file systems, a cluster (sometimes also called allocation unit or block) is a unit of disk space allocation for files and directories. To reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sectors by default, but contiguous groups of sectors, called clusters. On a disk that uses 512-byte sectors, a 512-byte cluster contains one sector, whereas a 4-kibibyte (KiB) cluster contains eight sectors. The term cluster was changed to allocation unit in DOS 4.0. However the term cluster is still widely used.
Depiction
Disk-structure.svg
DifferentFrom
Clustered file system
Computer cluster
Has abstract
enIn computer file systems, a cluster (sometimes also called allocation unit or block) is a unit of disk space allocation for files and directories. To reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sectors by default, but contiguous groups of sectors, called clusters. On a disk that uses 512-byte sectors, a 512-byte cluster contains one sector, whereas a 4-kibibyte (KiB) cluster contains eight sectors. A cluster is the smallest logical amount of disk space that can be allocated to hold a file. Storing small files on a filesystem with large clusters will therefore waste disk space; such wasted disk space is called slack space. For cluster sizes which are small versus the average file size, the wasted space per file will be statistically about half of the cluster size; for large cluster sizes, the wasted space will become greater. However, a larger cluster size reduces bookkeeping overhead and fragmentation, which may improve reading and writing speed overall. Typical cluster sizes range from 1 sector (512 B) to 128 sectors (64 KiB). A cluster need not be physically contiguous on the disk; it may span more than one track or, if sector interleaving is used, may even be discontiguous within a track. This should not be confused with fragmentation, as the sectors are still logically contiguous. A "lost cluster" occurs when a file is deleted from the directory listing, but the File Allocation Table (FAT) still shows the clusters allocated to the file. The term cluster was changed to allocation unit in DOS 4.0. However the term cluster is still widely used.
Hypernym
Unit
Is primary topic of
Data cluster
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enData cluster
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www.ntfs.com/hard-disk-basics.htm%23Sectors%20and%20Clusters
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Category:Computer file systems
Category:File system management
Disk fragmentation
Disk sector
DOS
File:Disk-structure.svg
File Allocation Table
File system
Interleaving (disk storage)
KiB
Kibibyte
Reading (computer)
Slack space
Track (disk drive)
SameAs
4o3r3
Allokeringsenhet
Bloc de système de fichiers
Cluster (bestandssysteem)
Cluster (Datenträger)
Cluster (pevný disk)
Clúster (sistema de archivos)
Data cluster
Dataklynge
Helyfoglalási egység
Klaster dyskowy
Kluster data
m.08bqc0
Q612728
Unidade de alocação
Unità di allocazione
Veri kümesi
Кластер (единица хранения данных)
Кластер записів
Клъстер (файлова система)
Податочен грозд
عنقود البيانات
クラスタ (記憶媒体)
데이터 클러스터
Subject
Category:Computer file systems
Category:File system management
Thumbnail
Disk-structure.svg?width=300
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Data cluster?oldid=1106263283&ns=0
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2810
Wikipage page ID
2906189
Wikipage revision ID
1106263283
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