Merge two existing libraries

[noimporta]

I have two full calibre libraries that I would like to merge.

Can I just copy the dirs from one into another? since the dirs have the cover and metadata file inside already or will it crash first's calibre database?

[Manichean]

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Originally Posted by noimporta

I have two full calibre libraries that I would like to merge.

Can I just copy the dirs from one into another? since the dirs have the cover and metadata file inside already or will it crash first's calibre database?

No, you can't just copy the folders into one another. That will overwrite the database belonging to one of the libraries with the one belonging to the other, resulting in Calibre only knowing the books from one of the two libraries. The other books will be orphaned in the library directory.
The proper way to do this is to copy the books to the library using Calibre's own copy mechanism: Open the library you don't want to keep, select all the books and right-click. There should then be an option to copy the books. Once the copy is done, you can open the other library, check if all books are there, and delete the library you don't want to keep.

[noimporta]

Thanks @manichean , i'm doing it right now. I hadn't found the calibre mechanism so what I was doing was importing like regular dirs with files inside from the add books menu, but it would take ages because it's a huge library so now I'm copying it the way you said.

[noimporta]

Now it crashed saying the disk where calibre primary library is full but it's not. I'm working with a network volume and there is plenty of space on it but calibre reports c: is full while calibre's primary library is on a networked volume z:.

Does this merge use the c: space instead for some mirroring?

Ok, now I see what's happening. When I switched the library to the new one (switching as in changing the folder in the library with switch/create library menu instead of having my two libraries library1 library2 I see library2 and Calibre Library that is in C: but I want to use both library1 and library2 which are in Z: , is there a way to do that? is maybe calibre mistaking the libraries because of library1 and library2 names?

Final update in my quest for the library merge. I deleted the new Calibre library that calibre created and switched again to library2, now library1 is listed and i'm on library2 (it doesn't show the current name under libraries or quick switch libraries) but when selected it recognized library1 as a library and let me copy and i can see refreshing the library1 directory list that it's being updated. So i'm happy! yey!