Synchronizing two or more libraries in Calibre

[bmeddings]

I have been using Calibre for several years.
Over those years I have backed up my Calibre Library.
My backup software and/or procedures have changed over those years.
So I now have a few copies of "Calibre Library" spread over multiple drives.

Is there any way to synchronize two somewhat different libraries ?
For instance, two of my libraries differ by a few hundred books as shown by the book count in Calibre.

I would be most grateful for any help or suggestions.

Baffled Basil

[BetterRed]

Originally Posted by bmeddings

Is there any way to synchronize two somewhat different libraries ?

I would probably use the Find Duplicates (optional plugin)->Find library duplicates on each backup library to identify and Mark the duplicate books, and then I'd use the built in Copy to library to move the unMarked books to the target library.

But I'd do some tests first to ensure I had the optimal combination of settings for the Find Duplicates plugin and Add Books.

I'd also do an incremental backup of the library as I moved each set of books.

BR

[PeterT]

What I've done in the past is to create catalogs in CSV format of multiple libraries and then use Excel to compare the lists.

Sent from my Nexus 7 using Tapatalk

[bmeddings]

My thanks to both BetterRed and PeterT.
I have some doubts about the "Find Duplicates" approach.
Probably both (say) BackUp_A and Backup_B will be free of duplicates inside each backup.
What I am after is a listing of the books that differ between Backup_A and BackUp_B.

The comparison between two .csv catalogs in Excel would work. But the prospect of spotting a few hundred discrepancies in several thousand entries is a bit daunting !

I have used "Total Commander" to list differences between the two libraries and the synchronise the libraries.
But although Total Commander then sees the two libraries as identical, Calibre still sees them as differing in book count by a few hundred.

I'm feeling a bit inadequate. Although that's not unusual at age 87 I'd still like to find a solution !

Still Baffled Basil

[BetterRed]

@bmeddings - the Find library duplicates feature of the Find Duplicates plugin will find books in Another Library that are duplicates of book in This Library - the matching author/title criteria algorithm can be set from 'exact' to 'fuzzy'.

I use the approach I outlined to ensure the books I have just added to my Intake library are not already in the Target library before copying them to the Target library. I import a dozen or more new 'books' a day.

But based on your comment regarding TC and Calibre count differences, I suggest you run Library Maintenance->Check library on each library before doing anything else. The last phase will compare the database, which is the source of calibre's book counts (as well as its heart and soul), with the library folders and report differences. If there are any differences, you should get those resolved first.

Differences are almost invariably caused when a file manager is used to add, delete, and rename folders and files within the calibre library folder.

BR

[bmeddings]

Thank you BetterRed, plus my apologies for not having understood your suggestion about "Finding Duplicates".

I have now run "Check Library" on all four of my Libraries.
Seemed to be quite a bit of deletion going on before everything was declared clean. Fortunately, the book counts all remained unchanged (also unequal).

What began the present kerfuffle was an accidental wipe of my main "D-drive' prior to doing a re-install of Windows 10 on my C-drive.

Most of that D-drive was re-instated from a backup copy.
But the backup appeared to lack some books from my Calibre_Library which was on D:\.

So what I'm really trying to do is to ascertain whether there are any books in any of my three backups of my Calibre-Library that are not on my present D:\Calibre-Library. Then import them into my D:\Calibre-Library.

I still cannot see how to do this.

As before, any suggestions will be received gratefully.

Basil

[DaltonST]

Originally Posted by bmeddings

So what I'm really trying to do is to ascertain whether there are any books in any of my three backups of my Calibre-Library that are not on my present D:\Calibre-Library. Then import them into my D:\Calibre-Library.

Basil,

You could Find all the Duplicates in a particular back-up as compared to your D:|Calibre-Library, and then "invert" the selection to capture the selection of all books that are not duplicates (i.e., are missing) from your D:|Calibre-Library.

To do the above, after you have run the Find Duplicates plug-in for Library-level duplicates, simply "mark" all of the results using CTL+M. Then, in the Calibre Search Bar specify "marked:false", and hit enter. Then, select all of the resulting books, Right-Click > Copy to Library > Calibre-Library.

Note that you might want to first rename D:\Calibre-Library so that the "Copy To" is different in the Calibre list of choices, which will of course offer all of your backups as the target recipient too. Use the standard Calibre "rename library" function to do this. Otherwise, you might end up copying the missing books to another backup library instead of D:\Calibre-Library if you are not careful. Or, you could also "Choose Library By Path" instead of selecting a specific Library Name. Whatever is easier for you.



DaltonST

[BetterRed]

@bmeddings - calibre is 'driven' by the content of its library database (metadata.db), not the subfolders and files within the library folder, however it does require that the latter to match with the database.

If you mess with the contents of the library folder with something like Total Commander's synchronisation feature (or anything similar), its almost certain to break the nexus between the database and file system folders and files. The golden rule with calibre library sub-folders and files is 'look but don't touch'.

Before doing anything else I recommend you use the calibre's Check library tool:-



Click OK/Yes on the messages and you will get to a dialogue that looks like this:-



The Help panel on the right explains the different error types, and what sort of corrections (Fix/Delete) can be done from that screen. After using the Fix and Delete options the Copy to clipboard can be used to get a hard copy of the remaining errors.

A simple way to 'sort out' the remaining errors is to use calibre's Copy to Library (delete after copy) feature to copy all the books from the existing library (oldLibrary) to a fresh library (newLibrary). The oldLibrary will then contain books that need to handled 'manually'. You could use Add books to add the books in the oldLibrary to the newLibrary using this option:-



Now you will have a clean library that you can 'compare' with the backup libraries using Find Duplicates->Find library duplicates.

I recommend you steer clear of the calibre library folders when you're in Total Commander, if you want to see what's in a book folder from calibre press 'O'.

I also recommend you run the check Library regularly, I run it before I do my weekly backups. Normally there are no errors, on the odd occasion there is one I can invariably account for it as a blunder on my part.

BR

[bmeddings]

Hallelujah !
Thanks to BetterRed and DaltonST I think I am now out of the woods. A very real "Thank you" to all of you.

In the process I was taught quite a bit about the capabilities of Calibre, although I have no doubt that there is one heck of a lot that I am still totally ignorant about.

So in a few days I've gone from four unequal Calibre libraries ranging from a Largest of 11,294 books down to Smallest of 10,157 books to four pretty equal libraries of 12,686 books each.

As I said, "Thank you" to everyone,
Cheers,
Brainless, but beaming, Basil