Sync two calibre libraries

[esears]

Both my wife and I use calibre on two different computers. We both use Sony readers, one a touch and the other a pocket. I tend to travel a lot and collect my own books to read. My wife has a bit different tastes than I do. Is there an easy way to sync two different calibre libraries on two different computers?
Is it just a matter of copying the directories from each computer to the other?

[kovidgoyal]

Do you mean you want both sets of libraries to have the same books?

[esears]

Originally Posted by kovidgoyal

Do you mean you want both sets of libraries to have the same books?

Yes, this is correct.

[kovidgoyal]

I use something called unison to acheive this. But you have to be careful not to run two copies of calibre simultaneously, as that will cause Bad Things To Happen.

[EricLandes]

What about using something like Dropbox and putting your library within Dropbox-controlled folders?

[jshoemaker]

Originally Posted by esears

Both my wife and I use calibre on two different computers. We both use Sony readers, one a touch and the other a pocket. I tend to travel a lot and collect my own books to read. My wife has a bit different tastes than I do. Is there an easy way to sync two different calibre libraries on two different computers?
Is it just a matter of copying the directories from each computer to the other?

You haven't mentioned what OS you're running, but I believe the rsync utility is available for windows, too. I've been using a custom rsync setup to keep the home directories of my desktop and linux netbook entirely synchronized for some time now. It works very well, even remembering where I was in each book when it syncs the calibre directory.

Something like this in a shell script will do the job:

rsync -Cuazv --delete-after --rsh=ssh --filter='merge ~/.rsync-filter' $1:~/ ~/

where $1 will become the ip of the remote box passed via command line. The file ~/.rsync-filter contains lines that direct what NOT to sync, usually stuff like

- /.**
- /tmp

So, when you run the rsync, it will sync everything in your home directory of the remote, minus the excluded merge. To update from the other machine, simply reverse the process. i.e., rsync -Cuazv --delete-after --rsh=ssh --filter='merge ~/.rsync-filter' ~/ $1:~/

It's a bit of work to set up initially, but not too bad. 20 minutes of work should see it completed. Use the -n flag to rsync while testing the setup - this forces it to do a 'dry run,' and not delete anything...

[daelic]

I store our collection on a network share, and just point both instances of Calibre to the that location. It works perfectly for us, but I'm the only one who adds new items to the share, the wife just uses it to see what's there and upload books to her reader.

[chainring]

Dropbox! It's available for the three major platforms and just flat out works.

[sherman]

Kovid, a thought..

Have you ever considered expanding the content server functionallity of calibre to achieve similar results?

Basically, from within calibre have some way of telling calibre to look at a remote calibre library and allowing the user to import/download books directly into the local library. Doing it this way would eliminate any complications arising from two instances of calibre sharing the same library...

Just an idea, have no idea whether it is doable or not, or whether you would be interested in implementing such a feature.

[jshoemaker]

Dropbox is limited to 2G for free users, or you get to pay, so the library had best be small. Won't work for a lot of us. (Mine is already well over 2G) There are a lot of exceptional free tools available, from unison to my obvious, time-tested favorite, rsync. I personally wouldn't vote to complicate the app more by having it do something already done better by a seperate utility, but if people have the inclination and time to burn, it may help a few people...

[kovidgoyal]

@sherman: Support for a proper "cloud" based library is on the TODO list.

[sherman]

Originally Posted by kovidgoyal

@sherman: Support for a proper "cloud" based library is on the TODO list.

Nice! I look foward to it whenever it happens

[DoctorOhh]

Originally Posted by jshoemaker

Dropbox is limited to 2G for free users, or you get to pay, so the library had best be small. Won't work for a lot of us.

Dropbox is not limited to 2G for free users, it starts out at 2G for free users. I have reached the limit of 5.25G for free users. You can get 250M for trying 5 of the 6 items under the getting started tab. You also get 250M for each person (up to 3G total extra) you refer who actually create an account and install the app.

2G free plus 3G for referrals and 250M for walking through the Getting Started tab make the final amount of free space possible 5.25G.

But you are right Dropbox isn't a solution that will work for everyone. I have 4 machines sync'd via Dropbox (2 at work and 2 at home) and it works great for me. My library is a little over 1100 books and weighs in at 675M so I have a ways to go before this solution will fail me.

[jshoemaker]

Originally Posted by dwanthny

Dropbox is not limited to 2G for free users, it starts out at 2G for free users. I have reached the limit of 5.25G for free users. You can get 250M for trying 5 of the 6 items under the getting started tab. You also get 250M for each person (up to 3G total extra) you refer who actually create an account and install the app.

2G free plus 3G for referrals and 250M for walking through the Getting Started tab make the final amount of free space possible 5.25G.

But you are right Dropbox isn't a solution that will work for everyone. I have 4 machines sync'd via Dropbox (2 at work and 2 at home) and it works great for me. My library is a little over 1100 books and weighs in at 675M so I have a ways to go before this solution will fail me.

I didn't delve into the fine print enough to notice that you are rewarded with extra space for inflicting the service on your enemies (I wouldn't recommend it to a friend, myself, for personal and practical reasons.)

I honestly don't know why this is such an issue here, but apparently it is. The job of synchronizing things is not an ebook application's forte; it is the job of a utility designed to synchronize. By far the oldest, most feature rich and adaptable solution is rsync, so that's what I use, and it synchronizes everything, not just ebooks.

For every app to have to provide a way to do this for its data just seems a bit silly to me, and is bound to create headaches as each implements it in a different fashion. I wanted my spreadsheets and documents sync'd, too, but I never expected OpenOffice to try to handle it... See my point? That's all I was pointing out, that this problem can, and has been solved with much more robust and applicable solutions.

[sherman]

The main problem I see with the directory based sync method is problems with the metadata.db file. Basically, you can only have a metadata.db file from one library or the other at a time. Now this isn't much of a problem if both libraries are always in sync right from the beginning. However...

What happens when you start off with only having one calibre library. You then go away with your laptop for a couple of weeks, and while you're away you start a new libary on your laptop. This new libary may include SOME books that are in the main library, and some books that are new. When you get home, you want to add the new books into the main library. But how would you do this using directory based syncing...?