Datadeduplikering

Datadeduplikering, often referred to as data deduplication or dedupe, is a technique used in data storage and backup systems to eliminate redundant copies of data. The primary goal is to reduce storage space requirements and, consequently, lower storage costs. It achieves this by identifying identical blocks of data and storing only one unique copy, while subsequent identical blocks are replaced with a pointer to the original stored block.

There are two main types of deduplication: block-level and file-level. File-level deduplication compares entire files to find duplicates. If an exact copy of a file is found, it is not stored again. Block-level deduplication is more granular, dividing data into fixed-size or variable-size blocks. These blocks are then compared for uniqueness. This method is generally more effective as it can identify duplicate data within different files.

Deduplication can be implemented in several ways, including in-line, where data is deduplicated as it is being written to storage, or post-process, where data is stored first and then deduplicated later. In-line deduplication saves space immediately but can add overhead to the write process. Post-process deduplication has less impact on write performance but requires initial space for the redundant data.

The effectiveness of deduplication depends on the nature of the data being stored. Highly redundant data, such as multiple backups of the same operating system or virtual machine images, benefit significantly from deduplication. Data with less inherent redundancy, like encrypted files or highly compressed media, will see less storage savings. Organizations employ data deduplication to optimize their storage infrastructure, improve backup efficiency, and manage growing data volumes more effectively.