Calibre works fine on a network share IF you understand that it must ALWAYS be single user. The issue isn't the network share, it's the multiple user access. Because, as theducks points out, you need to actually lock files and folders if you're going to allow multiple people to have access at the same time.
Doing this in a platform independent manner is usually done with a relational database where the smarts are built into the database. But changing to that kind of back end would turn Calibre into a very different program. Instead, to provide transparent access to your books at all times, even if Calibre goes away, Kovid and the developers have chosen what is, essentially, a flat-file system. I can perfectly understand that decision. Even though it's a minor nuisance for me personally. I'd still rather have it this way than to have all my books hiding inside a relational database.
|