I have a huge document library, in which there are thousands of document sets, containing more than 100,000 documents.
My task is to move the document library and its content, to another identical document library, which is on a different Sharepoint site, BUT on the same Office 365.
I tried out-of-the-box Sharepoint methods, but these only let you move one by one (and does not always work). Creating the whole document library as a template worked, but only as a layout. Trying to include the content simply does not work, probably because of the huge amount of documents.
I tried workflows using code: I did not even manage to get to the point of writing any code. Empty Sharepoint project just won't run on my local computer, and when I tried from a server which actually has Sharepoint installed, it still didn't let me connect to an external Sharepoint Online solution. I considered Sharepoint Apps but apparently you can't work with workflows in Apps. I also tried Sharepoint Designer but what I want to do just cannot be done using the Designer.
Then I got to know about CSOM and Powershell. First of all, can I move huge document libraries using either technology? And if yes, which do you suggest?
And how do I get started. This is my first time doing something Sharepoint related that is not simply Document Management using ready-developed Sharepoint features, but requiring actual code.
For CSOM, I did find this, which seems to be helpful, but I want to first literally manage to get started and then take it off from there:
So yep, any help appreciated! :)