File Sync via Windows Client (3.11.0) with Nextcloud Hub 6 (27.1.5) very slow / never ending

I recently installed a brand new NC instance (hosted webspace), run updates and enabled file encryption; have done this frequently in the past and have never had issues.

However, this time file sync via Windows Desktop Client 3.11.0 is slow and seems to never end.

Have found similar threads, but no solution so far:

We are talking about:

File upload never finishes (thats the problem case):

Connected the some client with an older NC instance at the some provider, but (23.0.0) with encryption as well; I used an exact copy of that folder I want to upload; upload works as expected and gets completed:

I created another user on that same problematic instance and upload another copy of the folder via Web Browser and everything seems to be fine (upload takes about 45 minutes … pretty smooth + straight forward):

Thanks for every hint, which might solve this ugly problem.

First of all, I would strongly recommend to process all issues form the Security & setup warnings, such as seting up cron jobs, a decent transactional file locking, add missing indexes like described in the linked manual. That would give your server a first perfomance boost.
Then it would make sense if you could provide log data, both from your server and your client, so that one can determine what exactly is slowing down your client.


1 Like

alright. noted. will do so and come back to you.

applied all the cahnges:

I started with a brand new user and a fresh sync yesterday, but file sync via Windows Client is still about to die / seems to never finish :-/ :


While the majority of the data is already online (26 GB in about 4.500 files; total = 29 GB in about 8.500 files) the remaining files (note screenshot above) take forever. It seems like every ~1 hour the progressed files jump 100 higher (from 500 to 600 … always in 100 files-steps). But as far as I remember from my sync issues above: Even it reaches the end it starts all over again … with again syncing this mysterious amount of 3.883 files in 2,5 GB - no clue what are so special with them.

It might probably has to do with the many small files as mentioned in other posts.

One more thing: I quickly analysed the delta files, those which havent been synced yet.

  • We are talking about 3.784 files and 1.022 folders (2,44 GB).
  • Files sizes are between 5 MB and 1 KB
  • 1.003 files are larger than 1.024 KB (those I wouldn’t consider to be small files)
  • 1.444 files are 10 KB and smaller

I think the “small file issue” does not really match here; at least, it cannot be the only reason.

And here are some updates from the super-slow file upload / file sync:
…three hours later …


…okay, maybe it is a bit more then 100 files per hour … in every case super slow.
Please be reminded of my upload test via Web-Browser where everything run smoothly.


this change basically solved my problem; no idea if Windows sync client now runs as fast as upload via web browser, but in every case in runs thru properly in a reasonable amount of time.

=> Very slow sync (for small files) - #13 by mooleshacat

The 3.883 files mentioned above were fully uploaded within 20 or 30 minutes!
No clue why this still needs to be added manually and isn’t part of the shipment … but

i am happy!

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