As a continuation for previous Zotero article, we want to introduce how to export and import Zotero library so user can use same library in many different computers or many different operating systems. It is very useful for time efficiency especially when a user has collected many references in one library in one computer, they don't need to repeat the effort in another computers or another OS.
Summary: after collecting some data in an instance of Zotero (e.g. in laptop with Ubuntu 14.04), we can export it to save the whole library collected. This method is very useful, for example, when the user does data collecting in a Live CD session.
How to: open Zotero (whether it is stand alone or attached in web browser) > click gear icon on top-left bar > select Export Library > select format Zotero RDF (the default) and check Export Files option > select destination folder to export > press Save.
The result: you will have a folder contains a zotero file and a folder. The inner folder contains all reference files you have collected (e.g. pdf or html web pages). You may archive this export folder to ease file distribution to another computers.
Summary: suppose you have an exported Zotero library. Now you use a new instance of computer (e.g. a freshly installed Ubuntu on laptop, or another OS). How to open your saved library of Zotero? Here is the method.
How to: open Zotero > click on gear icon on top-left bar > select Import > select the exported Zotero folder > select .rdf file inside that folder (i.e. MyLibrary.rdf) > wait for Zotero to import them > finish.
The result: you will have the imported library, the whole contents, imported in your Zotero. They are complete files, you can open them with exactly same results (e.g. no corrupted picture) like in the original system (edited 1 March 2016: read exception below). You can do search.
Edited 1 March 2016: exporting & importing with Zotero menu is not suitable for backup purpose. If you import a library, export it again, then import it again to another computer, you will find many missing files such as images, because Zotero export/import does not always export the files completely.