Calibre not playing well with git-annex

[Christopher Browne]

Running on Linux, version 0.7.44...

I was hoping to use git-annex (http://git-annex.branchable.com/) to manage copying bits of my library to different hosts.

"git-annex allows managing files with git, without checking the file contents into git. While that may seem paradoxical, it is useful when dealing with files larger than git can currently easily handle, whether due to limitations in memory, checksumming time, or disk space.

Even without file content tracking, being able to manage files with git, move files around and delete files with versioned directory trees, and use branches and distributed clones, are all very handy reasons to use git. And annexed files can co-exist in the same git repository with regularly versioned files, which is convenient for maintaining documents, Makefiles, etc that are associated with annexed files but that benefit from full revision control."

I "ran" git-annex against one of my Calibre library instances. This shifts all the "real" files into the git repository "object area," leaving symlinks. Calibre is fine with this, until I try copying some books onto my Kobo, at which point Calibre decides the book files can't be written to, and refuses to do the copy.

That is, in fact, correct; git-annex stows its documents in what it terms "WORM" files (e.g. - Write Once, Read Many), which get made read-only.

It seems unfortunate that copying a book from one place to another requires modifying it, and it seems to me that there would be value in having Calibre *mostly* have the invariant that it never writes to book files.

This might represent a rather deeper change than anyone wants to go into.

[Kovid Goyal (kovid)]

This is not worth the effort for me personally. If some one else wants to implement it, I will be happy to supply any needed guidance. If so, re-open the ticket and we can discuss it.

 status wontfix

[a-or-b (still-another-person)]

This is also an issue for me, but also leads to a bigger question:
  Why does Calibre need to have write access to existing book files in the library?

 Surely this means that backup software will flag changes when it doesn't seem that there would need to be any?

i.e. my file of Ulysses from Project Gutenberg shouldn't change whether it is on my ereader or not and so shouldn't need to be backed up if nothing else has changed...

Or am I missing something deep in the design of Calibre?

[Dmitry Ilyin (idv1985)]

I'm using Calibre with git-annex

You should not be using WORM backend for books, it's for really large files, i.e. videos, books are not that large.
Use SHA1E backend, it's fast and checksums content and you do want to do it.

Calibre usually doesn't modify the stored books unless it's asked to update the books metadata by "Embed Metadata".

Perhaps you have enabled something in the preferences?
Look into the Kobo device backend config, maybe there is something like metadata sync.