Cannot copy between libraries / cannot access library

[wddeam]

I am copying my library (210000 books) to a backup on an external harddisk (via USB3). After more than 85000 book haven been copied Calibre gives an error.

calibre, version 2.73.0
FOUT: Kopiëren van boeken mislukt: Kon geen enkel boek kopiëren, klik op 'Toon details' voor meer informatie.

Failed to copy 10 books, see below for details

Kopieren van: Letters From the Lost mislukt, foutmelding:
Traceback (most recent call last):
File "site-packages\calibre\gui2\actions\copy_to_library.py", line 156, in _doit
File "site-packages\calibre\gui2\actions\copy_to_library.py", line 194, in do_one
File "site-packages\calibre\db\legacy.py", line 246, in import_book
File "site-packages\calibre\db\cache.py", line 1569, in add_books
File "site-packages\calibre\db\cache.py", line 61, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 1529, in create_book_entry
File "site-packages\calibre\db\backend.py", line 822, in execute
File "c:\cygwin64\home\kovid\sw\build\apsw-3.8.2-r1\src\cursor.c", line 231, in resetcursor
CantOpenError: CantOpenError: unable to open database file

(I have deleted the error messages of the other nine books)

When I open the library I want to copy into I get another error

calibre, version 2.73.0
FOUT: Opstartfout: Er is een fout opgetreden bij het starten van calibre. delen van calibre functioneren mogelijk niet. Klik "Toon details" voor meer informatie.

Traceback (most recent call last):
File "site-packages\calibre\gui2\main.py", line 283, in initialize_db_stage2
File "site-packages\calibre\gui2\main.py", line 223, in start_gui
File "site-packages\calibre\gui2\ui.py", line 427, in initialize
File "site-packages\calibre\gui2\init.py", line 618, in save_layout_state
File "site-packages\calibre\gui2\library\views.py", line 538, in save_state
File "site-packages\calibre\gui2\library\views.py", line 532, in write_state
File "site-packages\calibre\db\cache.py", line 61, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 605, in set_pref
File "site-packages\calibre\db\backend.py", line 129, in set
File "site-packages\calibre\db\backend.py", line 125, in __setitem__
File "site-packages\calibre\db\backend.py", line 822, in execute
File "c:\cygwin64\home\kovid\sw\build\apsw-3.8.2-r1\src\cursor.c", line 231, in resetcursor
CantOpenError: CantOpenError: unable to open database file


When I want to delete a file in the 'copy to' library I get another error

calibre, version 2.73.0
FOUT: Niet afgehandelde fout: <b>CantOpenError</b>:CantOpenError: unable to open database file

calibre 2.73 [64bit] embedded-python: True is64bit: True
Windows-8-6.2.9200 Windows ('64bit', 'WindowsPE')
('Windows', '8', '6.2.9200')
Python 2.7.9
Windows: ('8', '6.2.9200', '', 'Multiprocessor Free')
Successfully initialized third party plugins: Quality Check (1, 9, 11) && Find Duplicates (1, 6, 2)
Traceback (most recent call last):
File "site-packages\calibre\gui2\actions\delete.py", line 404, in delete_books
File "site-packages\calibre\gui2\actions\delete.py", line 378, in do_library_delete
File "site-packages\calibre\gui2\library\models.py", line 385, in delete_books_by_id
File "site-packages\calibre\db\cache.py", line 61, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 1596, in remove_books
File "site-packages\calibre\db\backend.py", line 1621, in remove_books
File "site-packages\calibre\db\backend.py", line 834, in executemany
File "c:\cygwin64\home\kovid\sw\build\apsw-3.8.2-r1\src\cursor.c", line 231, in resetcursor
CantOpenError: CantOpenError: unable to open database file

What's wrong?

[theducks]

I suspect your A/V now has the DB open for scanning
OR
You are running Calibre library on a NAS, a no-no per the FAQ
OR
Your Cloud Sync (Library folder) was not paused

[PeterT]

Why not just copy the library at the OS level?