How to organize synchronization between cloud storages?

Question

Data synchronization

How can I organize synchronization between cloud storages? For example, synchronize folders between Dropbox and Yandex.Disk. Paid services like cloudhq.net usually work with only two or three large storages, and do not take into account the same Yandex.Disk or Mail.ru service. Maybe there is a software solution that could carry out such synchronization, even if it passes all the traffic through itself?

Answer 1

The easiest way is a symlink .
Each cloud in its own directory.
In one cloud there is a directory and info, and in the second cloud a symlink of this directory. At me so pictures are synced in 3 storages.
A good article about creating a symlink under Windows on geektimes.ru

Answer 2

here, multcloud.com (reflyer)
There is yandex. There is no Mail, but there is webdav.
But there is no daily free auto sync. You have to press the button each time to start the task

Answer 3

Have you tried nesting folders? For example, put the Yandex Disc storage in the Mail Cloud folder. And save all the files in Yandex, then they will be uploaded to both clouds at once. By the same principle, you can use any cloud.

Answer 4

@Freika suggests putting everything in one folder, but I don't think that's the best option.
Yandex.Disk and Dropbox, for example, store some kind of intermediate information in a folder inside their synchronized folder. Imagine that the POISON calculated something and put its meta-info, Dropbox saw the changes in the file (with the meta), recalculated and put it in its folder, this was seen by the POISON, etc. etc. Maybe someday they will agree...
Another way is to make a separate folder on the server for each service and mirror them all the time, bypassing the meta folders.
Both options do not solve the problem of conflicts when different files unexpectedly came from two clouds.