Browse Definitions :
Definition

cluster

1) In a computer system, a cluster is a group of servers and other resources that act like a single system and enable high availability and, in some cases, load balancing and parallel processing. See clustering.

2) In personal computer storage technology, a cluster is the logical unit of file storage on a hard disk; it's managed by the computer's operating system. Any file stored on a hard disk takes up one or more clusters of storage. A file's clusters can be scattered among different locations on the hard disk. The clusters associated with a file are kept track of in the hard disk's file allocation table (FAT). When you read a file, the entire file is obtained for you and you aren't aware of the clusters it is stored in.

Since a cluster is a logical rather than a physical unit (it's not built into the hard disk itself), the size of a cluster can be varied. The maximum number of clusters on a hard disk depends on the size of a FAT table entry. Beginning with DOS 4.0, the FAT entries were 16 bits in length, allowing for a maximum of 65,536 clusters. Beginnning with the Windows 95 OSR2 service release, a 32-bit FAT entry is supported, allowing an entry to address enough clusters to support up to two terabytes of data (assuming the hard disk is that large!).

The tradeoff in cluster size is that even the smallest file (and even a directory itself) takes up the entire cluster. Thus, a 10-byte file will take up 2,048 bytes if that's the cluster size. In fact, many operating systems set the cluster size default at 4,096 or 8,192 bytes. Until the file allocation table support in Windows 95 OSR2, the largest size hard disk that could be supported in a single partition was 512 megabytes. Larger hard disks could be divided into up to four partitions, each with a FAT capable of supporting 512 megabytes of clusters.

3) In some products, a cluster is a group of terminals or workstations attached to a common control unit.

This was last updated in April 2006

Continue Reading About cluster

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

In a NVR which hanged but the storage of previous records are available but further recording not done. How can I save that files and start recording without formatting hdds by using clusters.
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • California Consumer Privacy Act (CCPA)

    The California Consumer Privacy Act (CCPA) is legislation in the state of California that supports an individual's right to ...

  • compliance audit

    A compliance audit is a comprehensive review of an organization's adherence to regulatory guidelines.

  • regulatory compliance

    Regulatory compliance is an organization's adherence to laws, regulations, guidelines and specifications relevant to its business...

SearchSecurity

  • BlueKeep (CVE-2019-0708)

    BlueKeep (CVE-2019-0708) is a vulnerability in the Remote Desktop (RDP) protocol that affects Windows 7, Windows XP, Server 2003 ...

  • endpoint detection and response (EDR)

    Endpoint detection and response (EDR) is a category of tools and technology used for protecting computer hardware devices–called ...

  • ransomware

    Ransomware is a subset of malware in which the data on a victim's computer is locked, typically by encryption, and payment is ...

SearchHealthIT

SearchDisasterRecovery

  • disaster recovery team

    A disaster recovery team is a group of individuals focused on planning, implementing, maintaining, auditing and testing an ...

  • cloud insurance

    Cloud insurance is any type of financial or data protection obtained by a cloud service provider. 

  • business continuity software

    Business continuity software is an application or suite designed to make business continuity planning/business continuity ...

SearchStorage

  • blockchain storage

    Blockchain storage is a way of saving data in a decentralized network which utilizes the unused hard disk space of users across ...

  • disk mirroring (RAID 1)

    RAID 1 is one of the most common RAID levels and the most reliable. Data is written to two places simultaneously, so if one disk ...

  • RAID controller

    A RAID controller is a hardware device or software program used to manage hard disk drives (HDDs) or solid-state drives (SSDs) in...

Close