Article ID: kb00138Last Modified: 22-Aug-2024

Item-Level Restore for Volumes with Windows Deduplication

This article covers the following topics:

  • Item-Level Restore Support for Volumes with Windows Deduplication
  • Windows Deduplication Explained

Item-Level Restore for Volumes with Windows Deduplication

Starting from version 6.3.2, Backup for Windows supports item-level restore of volumes with Windows deduplication.

At the moment, an item-level restore is supported for volumes with Windows Deduplication only. If your target volume does not support Windows deduplication, the restore will fail

What is Windows Deduplication?

Windows deduplication is a feature that reduces the impact of redundant data on storage costs. Once enabled, Windows deduplication reduces the used space per volume by excluding duplicated parts on a volume.

Duplicated volume dataset parts are stored once and optionally are compressed for additional savings. Windows deduplication optimizes redundancy without compromising data integrity.

Once enabled for a volume, Windows deduplication runs in the background to:

  • Identify repeated patterns across files on that volume
  • Seamlessly move those portions, or chunks, with special pointers called reparse points that point to a unique copy of that chunk.

This occurs in the following steps:

  1. Scan the file system for files that match the optimization policy.
  2. Break files into variable-size chunks.
  3. Identify unique chunks.
  4. Place chunks in the chunk store and optionally compress.
  5. Replace the original file stream of now optimized files with a reparse point to the chunk store.

When optimized files are read, the file system sends the files with a reparse point to the Data Deduplication file system filter (dedup.sys).

System Requirements

Windows deduplication works on the following operating systems:

  • Windows Server 2016
  • Windows Server 2019.
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