Does Borg deduplication detect identical data after splitting it across multiple disks?

[blueray453]

I previously had all my data on a single large HDD, which I backed up using Borg into one repository.

Now I want to split that data across two smaller HDDs (say, HDD1 and HDD2).

Here’s an example of what I mean:

# Before (single HDD)
 /mnt/oldhdd/data/
 ├── Documents/
 │   ├── report.pdf
 │   └── notes.txt
 └── Pictures/
     ├── img001.jpg
     └── img002.jpg

# After (split across two smaller HDDs)
 /mnt/hdd1/
 └── Documents/
     ├── report.pdf
     └── notes.txt

 /mnt/hdd2/
 └── Pictures/
     ├── img001.jpg
     └── img002.jpg

I plan to back up both of these new drives into my existing Borg repository (the one that was created from the old single HDD).

borg create /mnt/oldhdd/repo::new-backup /mnt/hdd1 /mnt/hdd2

My question is:

Since the underlying file contents haven’t changed, will Borg’s deduplication detect that most chunks already exist in the repository (based on content hashes) and avoid re-uploading them?

Or will it treat everything on these drives as new files and back up all the chunks again?

[infectormp]

Since the underlying file contents haven’t changed, will Borg’s deduplication detect that most chunks already exist in the repository (based on content hashes) and avoid re-uploading them?

yes

[blueray453]

Thank you very much.