Browse Definitions :
Definition

write back

Contributor(s): Stan Gibilisco

Write back is a storage method in which data is written into the cache every time a change occurs, but is written into the corresponding location in main memory only at specified intervals or under certain conditions.

When a data location is updated in write back mode, the data in cache is called fresh, and the corresponding data in main memory, which no longer matches the data in cache, is called stale. If a request for stale data in main memory arrives from another application program, the cache controller updates the data in main memory before the application accesses it.

Write back optimizes the system speed because it takes less time to write data into cache alone, as compared with writing the same data into both cache and main memory. However, this speed comes with the risk of data loss in case of a crash or other adverse event.

Write back is the preferred method of data storage in applications where occasional data loss events can be tolerated. In more critical applications such as banking and medical device control, an alternative method called write through practically eliminates the risk of data loss because every update gets written into both the main memory and the cache. In write through mode, the main memory data always stays fresh.

This was last updated in July 2012

Continue Reading About write back

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

thanks 

Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • 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...

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

SearchSecurity

  • RSA algorithm (Rivest-Shamir-Adleman)

    The RSA algorithm is the basis of a cryptosystem -- a suite of cryptographic algorithms that are used for specific security ...

  • remote access

    Remote access is the ability to access a computer or a network remotely through a network connection.

  • IP Spoofing

    IP spoofing is the crafting of Internet Protocol (IP) packets with a source IP address that has been modified to impersonate ...

SearchHealthIT

SearchDisasterRecovery

  • virtual disaster recovery

    Virtual disaster recovery is a type of DR that typically involves replication and allows a user to fail over to virtualized ...

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

SearchStorage

  • enterprise storage

    Enterprise storage is a centralized repository for business information that provides common data management, protection and data...

  • disk array

    A disk array, also called a storage array, is a data storage system used for block-based storage, file-based storage or object ...

  • optical storage

    Optical storage is any storage type in which data is written and read with a laser. Typically, data is written to optical media, ...

Close