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Inline deduplication

Inline deduplication definition

Inline deduplication is a method used to get rid of duplicate data stored on computer systems. It works by removing duplicate data as it's being saved to storage, meaning it removes duplicates right away, as data is being written. The opposite approach is called post-process deduplication. With post-process deduplication, duplicate data is identified and removed after it's already been saved into storage.

See also: data deduplication

How does inline deduplication work?

  • When data is being saved to storage, inline deduplication checks if it's similar to any data already stored.
  • If the data matches something already saved, it's flagged as a duplicate.
  • The duplicate data is removed before it's actually stored, freeing up space.
  • The unique data is then saved to storage as usual — just without any duplicates.

Drawbacks of inline deduplication

  • Inline deduplication can slow down data writing because it needs to process data in real time.
  • It may need more processing power or specialized hardware to handle the real-time deduplication process efficiently — and such hardware can be expensive.
  • It also needs careful planning and understanding of data types to ensure effective deduplication without compromising performance or data integrity.
  • It may not work well when you need to accommodate growing data volumes.

When should you use inline deduplication?

  • When you don’t have much space on the device you’re transferring data to. That way, you’ll only need space for the compressed and deduplicated data, not for the original.
  • When you need to make sure your computer systems keep running smoothly and don’t know how much space you can save without slowing things down.
  • When you know that the data has a significant number of duplicates. By using inline deduplication, you’ll write less data and reduce the wear on the disk.