HDD deduplication not starting

[Feathered-Serpent]

Hey there. I used the --hdd option and restarted the NAS. When running the script now it says:

Synology_enable_Deduplication v1.4.33
DS1621+ DSM 7.3.2-86009-4

StorageManager 1.0.1-1100

Using options: --hdd
Running from: /volume1/Tools/Synology_enable_Deduplication/syno_enable_dedupe.sh

NAS has 36 GB of memory.

Non-Synology drive support already enabled.

Btrfs Data Deduplication already enabled.

Dedupe config menu for HDDs and 2.5" SSDs already enabled.

Finished

I configured the automatic deduplication only to see, it still shows to never have run:

And when I disable the automatic deduplication and run the deduplication manually, it runs for only a second or two, before the button is back to "Ready" and nothing happened.

Am I doing something wrong?

[Feathered-Serpent]

Addendum: Volume 3 is on a DX-517 Expansion Unit.

[Feathered-Serpent]

the following log files have been changed from Synology, when I tried the Run Now:
systemd.log
2026-07-18T20:07:46+02:00 DragonsWatch systemd[1]: Started Synology Btrfs Deduplication Service.

synosystemd.log
2026-07-18T20:07:46+02:00 DragonsWatch synoscgi_SYNO.Storage.CGI.BtrfsDedupe_1_manual_dedupe[27603]: systemd_start.cpp:16 synosystemd: [synobtrfsdedupe] starting ...
2026-07-18T20:07:46+02:00 DragonsWatch synoscgi_SYNO.Storage.CGI.BtrfsDedupe_1_manual_dedupe[27603]: systemd_start.cpp:20 synosystemd: [synobtrfsdedupe] started.

synobtrfsdedupe.log:
2026-07-18T20:07:46+02:00 DragonsWatch synobtrfsdedupe[17286]: Delete subvol 6fad0b5b-a585-8842-86e6-142de21b671a from config and sample index
2026-07-18T20:07:46+02:00 DragonsWatch synobtrfsdedupe[17286]: dedupe/service/service_operation_worker.cpp:15 Exception (dedupe/index/sample_index.cpp:53): Sample index not found: /volume3/@Dedupe

When checking the /volume3/@dedupe/dedupe.conf file. I get this:

[Feature]
Version=86009
[Subvol Table]
0001=258,6fad0b5b-a585-8842-86e6-142de21b671a
0003=260,5c48c300-48a9-0041-bb81-39dae89aa91f
0000=257,40710ec6-0ef5-3d49-a5d5-2488fcf40d56
0002=259,b48926df-528a-8246-8bcc-b0741ea9b1a1
[Status]
Last Dry Run Scan=1699603779584
Share and LUN used=16644445974528
Automatic Scanned=0
Automatic Need Account=true
Last Dry Run Estimated=68604781772
Automatic Released=0
Last Dry Run Time=1783376061.341850697
Need Dedupe Data=17688241156096
Total Data=17688241156096
Total Data Update Time=1784352733.564403111

[007revad]

I wonder if deduplication only works on drive in the NAS itself.

I'll hook up my DX213 to my DS1821+, and some duplicate data and see if I get the same results.

[007revad]

A manual run worked on the volume in my DX213... though it only save 412 KB.

[Feature]
Version=86009
[Subvol Table]
0000=258,a6204b36-6d85-b345-b540-0869820c08ab
[Status]
Dedupe Full Max Scan=195499749376
Last Dedupe Full Time=1784441287.955180163
Dedupe Full Max Scan Savings=421888
Last Dedupe Full Savings=421888
Last Dedupe Full Scan=195499749376

What does this command return?

sudo ls -l /volume3/@dedupe

[007revad]

Try disabling deduplication for volume 3, or all volumes, then enable it again.

[Feathered-Serpent]

sudo ls -l /volume3/@dedupe
total 4
-rw------- 1 root root 544 Jul 18 20:22 dedupe.conf
-rw------- 1 root root   0 Jul  6 23:14 reset_list

Volume2 is a non-Synology-NVME-Storage Pool (in the main unit) where Dedup is working:

sudo ls -l /volume2/@dedupe
total 571136
-rw------- 1 root root       787 Jul 18 17:30 dedupe.conf
-rw------- 1 root root 402653040 Jul 18 16:30 dup
-rw------- 1 root root 268435456 Mar 28  2025 hole.cow
-rw------- 1 root root 268435456 Mar 28  2025 hole.nocow
-rw------- 1 root root         0 Jul 18 17:30 reset_list
-rw------- 1 root root 182184306 Jul 18 16:30 sample

I'll try the disabling (though only volume2 and now volume3 have it enabled) and enabling. Would I have to restart the NAS in between?
Edit: you mean just take the volume out of the dedup scheduler? or disable dedup completely with --restore?