{"id":5711,"date":"2020-10-09T14:18:09","date_gmt":"2020-10-09T12:18:09","guid":{"rendered":"https:\/\/tekmart.co.za\/t-blog\/?p=5711"},"modified":"2020-10-09T14:18:11","modified_gmt":"2020-10-09T12:18:11","slug":"differential-backup-a-tech-definition","status":"publish","type":"post","link":"https:\/\/tekmart.co.za\/t-blog\/differential-backup-a-tech-definition\/","title":{"rendered":"Differential Backup-a tech definition"},"content":{"rendered":"Reading Time-approximately:<\/span> 3<\/span> minutes<\/span><\/span>\n

A differential backup is a\u00a0data backup\u00a0that copies all of the files that have changed since the last full backup was performed. This includes any data that has been created, updated or altered in any way and does not copy all of the data every time. The term differential backup stems from the concept that only data that is “different” is copied.<\/strong><\/h2>\n\n\n\n
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Posted by:\u00a0Margaret Rouse<\/a><\/p>\n\n\n\n

WhatIs.com<\/a><\/p>\n\n\n\n

Contributor(s):\u00a0Sarah Lewis<\/a>\u00a0and\u00a0Sonia Lelii<\/a><\/p>\n\n\n\n

How do differential backups work?<\/strong><\/h3>\n\n\n\n

Differential backups start with a\u00a0full backup, or the process of making a copy of all files in a data repository. Once the original full backup is performed, differential backups use it as a snapshot for comparison and to carry out subsequent backups. Then, as files are created or changed before the next full backup, they are flagged. Organizations will designate\u00a0the differential backup schedule, and once initiated, the\u00a0cumulative backup data\u00a0will be copied.<\/p>\n\n\n\n

Why use differential backups<\/strong><\/h3>\n\n\n\n

The idea behind using differential backups stems from saving storage space and restoration time. Since there are often less changes to data compared to the amount of files within a data repository, the backup will take less time to perform than a full backup.<\/p>\n\n\n\n

Full backups ensure the highest level of data security, however, they are not practical for companies to perform regularly as they take up time and resources. Therefore, organizations turn to differential backups as an alternative method to protecting critical or sensitive information.<\/p>\n\n\n\n

While differential backups can increase organizational efficiency, one major consideration is balancing out the full backup cycle. If too many differential backups are executed prior to the next full backup, the size of the differential backup may grow larger than the original baseline. <\/p><\/blockquote>\n\n\n\n

This may create a few redundancies as some files may be included in earlier differential backups that are then left unchanged, but continue to get backed up repeatedly until the next full backup. Due to this, some\u00a0data backup software\u00a0vendors have begun to incorporate triggers that automatically initiate a full backup if differential backups reach a certain size.<\/p>\n\n\n\n

Differential backup vs. incremental backup<\/strong><\/h3>\n\n\n\n

Differential backups are often confused with incremental backups as each method only copies new, altered or updated files. However, an incremental backup process compares changes to the state of the data since the\u00a0previous\u00a0backup \u2013 whether it was a full backup\u00a0or incremental. For example, if a full backup was performed on Monday, Tuesday’s incremental will back up all new or changed files since Monday’s backup. However, Wednesday’s incremental will only back up files that have changed since Tuesday’s incremental backup and so on until another full backup is performed.<\/p>\n\n\n\n

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While differential and incremental backups have similarities, this graphic compares the two methods to a full backup.<\/strong><\/figcaption><\/figure>\n\n\n\n

These smaller sets of data are then used to create a series of individual backups that represent the full, up-to-date copy. With differential backups, each day\u2019s changes are compared to the original full backup, making a more cumulative series of data copies.<\/p>\n\n\n\n

Incremental backups copy fewer files and thus take up less storage capacity. However, the restore process may take longer than differential backups since the software used for recovery needs to rebuild the data from the most recent full backup as well as the separate incremental backups. In order to combat this issue, the multi-level incremental backup method developed as a solution. This variation of incremental backups is most similar to differential backups as it assigns backup levels that can span over multiple days or backups.<\/p>\n\n\n\n

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