Help - Library is suddenly empty

[Kraftwerk]

Version 2.33 64bit (was about to update to 2.45 until I found the library empty!)

Is there anything I can do to get the library back?

How can it suddenly be empty?
The folder is empty except for: 'metadata.db' and 'metadata_db_prefs_backup.json'.

I have my books saved on an external harddrive, but before I start adding the books back to the library is there anything I should do to fix corruption etc. before I add the books back to the library, or is there something I can do that might return the books?

Thanks

[eschwartz]

http://manual.calibre-ebook.com/faq....libre-is-blank

[Kraftwerk]

Originally Posted by eschwartz

http://manual.calibre-ebook.com/faq....libre-is-blank

I clicked on 'restore database', but it's still blank.
Looks like all the books have been deleted?

[BetterRed]

@Kraftwerk - I think this could happen if you did a Ctrl+A on the book list to select all books, and then you inadvertently hit the Delete key - and you either ignored this warning



Or on a previous occasion you have unchecked "Show this warning again".

BR

[Kraftwerk]

Originally Posted by BetterRed

@Kraftwerk - I think this could happen if you did a Ctrl+A on the book list to select all books, and then you inadvertently hit the Delete key - and you either ignored this warning

Attachment 144177

Or on a previous occasion you have unchecked "Show this warning again".

BR

I can't remember doing that, but you never know.

I've transferred all books back into the library folder (which were saved on an external hard drive), so everything is back to normal now.

[BetterRed]

Originally Posted by Kraftwerk

I can't remember doing that, but you never know.

I've transferred all books back into the library folder (which were saved on an external hard drive), so everything is back to normal now.

@Kraftwerk - you can click a button in Preferences->Behaviour to reset the 'are you sure' messages.

Glad you got your library back - demonstrates the value of taking regular backups.

BR

[Kraftwerk]

Originally Posted by BetterRed

@Kraftwerk - you can click a button in Preferences->Behaviour to reset the 'are you sure' messages.

Glad you got your library back - demonstrates the value of taking regular backups.

BR

I've reset the 'messages'.

One other question:

What information is kept in 'metadata_db_prefs_backup.json'?
Is it the information for plugins, because if it is, I can stop saving the 'calibre configuration directory'?

[eschwartz]

No, plugins store their configuration in the calibre configuration directory.

"metadata_db_prefs_backup.json" contains library-specific information -- basically, anything that is stored in the metadata.db

This includes custom column configuration, which columns are shown/hidden/ordered, saved searches/virtual libraries, etc.

Some plugins store extra info in the database, for example, the OverDrive Link plugin stores the "Discovered Books" in the database.

[BetterRed]

Originally Posted by Kraftwerk

I've reset the 'messages'.

One other question:

What information is kept in 'metadata_db_prefs_backup.json'?
Is it the information for plugins, because if it is, I can stop saving the 'calibre configuration directory'?

@Kraftwerk - that file contains a copy of the settings/preferences/customisations which are library specific, the values that are actually used are stored in the library database itself. It is only used by the Library Maintenance->Restore Database function; as are the metadata.opf files in the book folders.

The 'calibre configuration directory' contains global settings/preferences/customisations. It also has plugins themselves, some plugins store settings there (Count Pages), some plugins store settings there and in the database (Reading List) and others only in the database (View Manager).

So my advice is - backup library directories and calibre's configuration directory - preferably at the same time, and as often as possible. I do incremental backups of both (along with everything else) on a daily basis.

BR

[Kraftwerk]

Thanks to the above two replies.
Very helpful.