Syncthing deduplication ioctl FICLONE

Feature
1

I have one file in multiple directories (for example jpeg in my family photo album and same file on my android phone backup). I have XFS filesystem which supports reflink (deduplication - ioctl FICLONE).

Would it be possible to support this feature in syncthing ? It seems it is not supported because duperemove always frees some disk space.

Thanks!

2

It is, but not enabled by default: copyRangeMethod — Syncthing documentation

3

Great!

and is it stable enough ? Which one from those you recommends ?

Thanks much.

4

Would it be possible to deduplicate shares from web GUI? Syncthing should have information about identical blocks/files.

Also it would be nice to fallocate files if they are filled with zeros (create sparse files)

5

You will have to experiment with which methods works for you based on the documentation. There is no after-the-fact deduplication. Sparse files are the default though, always.

6

Ok thanks

cp --reflink is using: ioctl(4, BTRFS_IOC_CLONE or FICLONE, 3) = 0

so I’ll try ioctl