5

Using Windows Server's data deduplication feature:

Given a specific chunk file in the chunk store, is it possible to determine which file/s include that chunk?

The use case here is that unreadable blocks on the disk can be mapped back to the chunk file, meaning that corruption may have occurred in that specific chunk file, and I would like to know what file/s use that chunk, so I can manually check whether those file/s appear to be corrupted in any way, and/or assume they are corrupted and restore them etc.

***Logical sector 4298505920 (0x10035fec0) on drive X is in file number 144581.
\System Volume Information\Dedup\ChunkStore\{F3F1DCDF-134B-4A3E-AFD5-5F698E42667A}.ddp\Data\000004ad.00000001.ccc

In other words, can I find out what file/s are using the data in the above chunk file?

Ned Martin
  • 181

1 Answers1

2

As far as I am aware, Windows Server's data deduplication feature does not provide a way to return to files that use chunks. But there are a few ways to figure out if there are any connections:

PowerShell and Deduplication Cmdlets: Utilize PowerShell cmdlets related to data deduplication. Get-DedupStatus and Get-DedupMetadata may provide insight into duplicate volumes and the associated metadata.

Get-DedupStatus -Volume X:
Get-DedupMetadata -Path "X:\System Volume Information\Dedup\ChunkStore\{F3F1DCDF-134B-4A3E-AFD5-5F698E42667A}.ddp\Data\000004ad.00000001.ccc"

I copied these commands out of a real, but ancient doc that I had, but it had some formatting errors. You might need to use, maybe combined with a pipe.

Check File Metadata: Although this won't directly link to specific chunks, it can help identify files associated with a particular disk area.

Get-Item "X:\System Volume Information\Dedup\ChunkStore\{F3F1DCDF-134B-4

But in fact, there is no direct feature from Windows that fit your Approach as I remember in my 20+ Years of Knowledge in IT. It may also be possible that some kind of Third-Party Application can read that kind, but none is known to me nor was required due NTFS always did an impressive outstanding Job with its DD-Feature.

djdomi
  • 2,287