Library Deletion with Calibre Error

[oldronin]

Hey folks,

I should start by saying that I love Calibre. I've been using it for quite a while and it works fantastically well. I hit a horrible snag recently and it's most likely my fault, but I wanted to be sure.

My library is more than 23GB is size and I've been hosting the client on a Win 7 machine. I had a Windows Home Server hosting the calibre library with no problems (beyond slow processing). I moved my library to a Synology DS412+ last June and everything has been working fine. I'm just pointing the client to a library folder on the Synology drive.

As I said, it's all been working fine. However, twice in the past two weeks my entire library has been wiped out. I get the error below, have to close the client and when it's restarted the library is gone. When I look at the folder on the Synology server, the recycle folder doesn't have the the library files, just metadata files. Attempts at a library recovery are unsuccessful.

Since this happened again today, I did a search and found there are some known issues with Synology, although it was hard to understand if it was just with running the client from Synology and/or the library.

My questions:
1. It seems really odd, but should I just write off the successful run of hosting Synology as my library for the past eight months as dumb luck?

2. I update my Calibre client every week. Is it possible something changed in the recent updates to contribute to this problem?

3. I use the Synology as a library host due to the size of my library. Is that possible or does anyone know if it will be possible in a future update? Alternatively, can I host it on a USB drive to offset the space requirement from my main machine?


Calibre Error Output -----------------------------------------
calibre, version 1.28.0
ERROR: Unhandled exception: <b>CantOpenError</b>:CantOpenError: unable to open database file

calibre 1.28 [64bit] isfrozen: True is64bit: True
Windows-7-6.1.7601-SP1 Windows ('64bit', 'WindowsPE')
('Windows', '7', '6.1.7601')
Python 2.7.5
Windows: ('7', '6.1.7601', 'SP1', 'Multiprocessor Free')
Traceback (most recent call last):
File "site-packages\calibre\gui2\ui.py", line 905, in closeEvent
File "site-packages\calibre\gui2\ui.py", line 804, in write_settings
File "site-packages\calibre\gui2\init.py", line 497, in save_layout_state
File "site-packages\calibre\gui2\library\views.py", line 498, in save_state
File "site-packages\calibre\gui2\library\views.py", line 492, in write_state
File "site-packages\calibre\db\backend.py", line 115, in set
File "site-packages\calibre\db\backend.py", line 111, in __setitem__
File "site-packages\calibre\db\backend.py", line 791, in execute
File "c:\cygwin\home\kovid\sw\build\apsw-3.7.14.1-r1\src\cursor.c", line 231, in resetcursor
CantOpenError: CantOpenError: unable to open database file

Thanks in advance for any responses or help on this item.

[BetterRed]

Originally Posted by oldronin

My questions:
1. It seems really odd, but should I just write off the successful run of hosting Synology as my library for the past eight months as dumb luck?

See ==>> http://manual.calibre-ebook.com/faq....rked-drive-nas

Essentially calibre is a single user system. Whilst it might work some of the time on a Server or NAS, there's no guarantee it will work all of the time or into the future. Some people get away with doing it, some don't.

Originally Posted by oldronin

2. I update my Calibre client every week. Is it possible something changed in the recent updates to contribute to this problem?

Possibly, although i doubt it. But as you've been getting away with running calibre in an unsupported environment then... you know the rest.

Originally Posted by oldronin

3. I use the Synology as a library host due to the size of my library. Is that possible or does anyone know if it will be possible in a future update?

Yes probably, but when isn't certain. Calibre is not developed to a calendar bound delivery schedule like commercial software. I imagine there'll be a beta release for the version that supports server hosted libraries.

Originally Posted by oldronin

Alternatively, can I host it on a USB drive to offset the space requirement from my main machine?

Absolutely you can. And if its thumb or 2.5" drive you might want to put calibre portable onto it so you can carry the the whole kit and caboodle around in your pocket/purse. I'd say this your best choice, especially if you can use a USB3.0 drive.

BR

[kovidgoyal]

Do not put your calibre library on a network drive: http://manual.calibre-ebook.com/faq....rked-drive-nas

[DoctorOhh]

Originally Posted by oldronin

As I said, it's all been working fine. However, twice in the past two weeks my entire library has been wiped out. I get the error below, have to close the client and when it's restarted the library is gone. When I look at the folder on the Synology server, the recycle folder doesn't have the the library files, just metadata files. Attempts at a library recovery are unsuccessful.

Just a FYI. Your "entire library" wasn't wiped out only the metadata.db file (was corrupted) which holds all of the info you see in the GUI about the library.

As others have pointed out it might be best to run calibre locally and sync it to your NAS.

[oldronin]

Thanks for all of the quick replies! I'll give an attached USB drive a chance to see if that works. If not, I'll do it locally and just use the Synology as a backup copy.

[theducks]

Originally Posted by oldronin

Thanks for all of the quick replies! I'll give an attached USB drive a chance to see if that works. If not, I'll do it locally and just use the Synology as a backup copy.

USB connected Hard Drives work quite well.
IMHO go for a Drive enclosure that has external power rather than powered from the USB port, Then you can install a higher performance drive. Many retail USB drives are fine for backups where speed is not normally an issue. OTOH putting a 10K RPM drive on a USB2 connection is overkill