Sync only the file change, not entire file [$1,755]

[wesleyhuang]

In Dropbox, there notes that only the file changes are sync-ed, not the entire file. https://www.dropbox.com/help/8/en. It is great if ownCloud can do the same. Especially for large files, sync-ing the entire files make a lot of bandwidth and time unnessararily wasted.

In my testing with latest 4.5.4 and sync client in Ubuntu 12.04, I prepared a 1GB text file, append a few characters to the end, and monitor the traffic and the file in the server, I see the entire 1GB file is transffered to the server and the server is actually creating a new file.

A reply from the forum indicates that librsync has this feature http://librsync.sourceforge.net/, maybe the csync can be switched to the libsync.

[allo-]

i think this is ESSENTIAL for a sync client. And detecting of moved files. Maybe combining this like rsync -y (trying to find a similiar base file on the remote side to speedup upload), but note that rsync -y can slow down (lib)rsync when working in large directories.

[rarspace01]

any update on this?

[LoZio]

+1 for this. There's a wealth of files that may slightly change each time and are big to sync. Outlook PST, truecrypt, databases, phone backups, ...
Any update on this?

[jmstacey]

I'd like to see this as well.

[Dont-ask-for-it]

Waiting on this to install my first owncloud server.

[notDavid]

I hope this will be implemented, seems essential..

• for some reason my ownCloud client (1.3.0, OS X) has trouble syncing big files with small changes, and always re-uploads entire files...

[tityrus]

I also see this as essential. Please.

[xeloader]

I agree on this one as well, we need to be able to have some kind of incremental sync possibility before this is 100% usable.

[dragotin]

The problem is known, and we will get to it. At one day.

Until then, please try to retain from +1 comments ✌️

[Poelziminator]

Can you give an estimate when will see the “one day”?
This functionality would open up whole new possibilities like syncing Truecrypt-volume files or Lightroom catalogs.

[danimo]

@Poelziminator Not in any release this year. Note that most work for this will be in the server and the general design.

[zwo-bot]

This is the key-feature for everone works with trucrypt or bigger dbfiles. Please make it happen.

[jancborchardt]

This as well seems related to the 1.6 »Sync Performance« milestone. @MTRichards @dragotin @danimo?