Long file names and large files result in error

My owncloud provider has a limit of 148 bytes for the filename. As i understand it, thats a limit they are enforcing, not one that is enforced by owncloud
The issue is that i can create a file with a filename length of 145 bytes and fill it with data.
If the size of the file is small (like 5MB or so) the owncloud Windows Desktop client syncs properly
If the size of the file is 10MB or larger the owncloud Windows Desktop client returns the error "Connection closed"
If i decrease the filename length to 137 bytes, the 10MB+ file syncs properly again

Expected behaviour

Sync the file

Actual behaviour

I receive a "connection closed" error

Steps to reproduce

  1. Create a file with a filename as close as possible to the filename limit
  2. Fill the file with data until its at least 10MB in size
  3. Wait for it to sync
  4. Decrease the filename length as needed until the file syncs properly

Server configuration

Operating system: Unknown
I'm only a client so i'm not familiar with the server environment

Web server: Unknown


PHP version:Unknown

ownCloud version:Unknown

Storage backend (external storage):Unknown

Client configuration

Client version: 2.4.0 and 2.2.4

Operating system: Windows 10 1709

OS language:English

Installation path of client:Default


Please use Gist (https://gist.github.com/) or a similar code paster for longer

#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)
|0|aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.txt|INST_SYNC|Up|1520147589||10010000||1|Connection closed|0|5005000|1520147581|1518a62be3d68cb34c5ec8|155768|INST_NONE|
#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)
|0|aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.txt|INST_NEW|Up|1520147589||10010000||1|Connection closed|0|0|0|||INST_NONE|
#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)
#=#=#=# Syncrun started  until  (0 msec)

Correct me if i'm wrong: I think the client can't successfully sync a file if the server / your provider is enforcing limitations making such a sync impossible.

Maybe you can contact the support of your provider asking for help in this case? Especially if you're only a client of this provider there is probably not much what can be done here by the community or by you.

The limit is supposedly 148 bytes according to them
In my example i use 145 bytes which is below that limit. The problem is, is that the behavior is different based on the file size

Just an idea: Some tools append an additional extension to the filename, like ".part".

Yes but the lengths specified are including the extension so it does not apply

I still think it might be a good idea to contact the support of your provider for some help and to remove that limit from their side. As long as there is such a limit in place i think the users in this forums here can't do much about that. :confused:

Ah, i have just remembered that i have read somewhere (maybe in the documentation?) that the sync client is uploading files over a specific file size in "chunks". Maybe they are using some file extensions like mentioned by @alfredb above and then it could explain the differences you're observing.

It has already been reported to them. But wanted to know whether this was something familiar here.
It might be the chunks... the thing is is that this issue was not present before they upgraded the owncloud environment
Don't know what versions of the server were upgraded but the Windows desktop client went from 2.2.4 to 2.4.0
Is the chunks thing a recent adjustment on the server side?

Maybe you can find some info about this at the changelogs and release notes of server and client?