Problems with library located on a network drive

mikolajek · 07-02-2014, 07:28 AM

I've switched from a desktop PC to a notebook which resulted in migrating many of my files into NAS drives. That included Calibre library.

After a fresh Calibre install I was unable to add book or modify books in the library but I found the answer on the forum and followed that - deleted the metadata.db file and recreated library. There was some minor errors related to two books but in general that worked.

Unfortunately I'm not able to add new books to the library - Calibre claims to have added some of them (not listing them in the error dialog) but it's not true. The most recent error that keeps appearing is lited below:

Quote:

calibre, version 1.42.0
ERROR: Unhandled exception: <b>CantOpenError</b>:CantOpenError: unable to open database file

calibre 1.42 [64bit] isfrozen: True is64bit: True
Windows-8-6.2.9200 Windows ('64bit', 'WindowsPE')
('Windows', '8', '6.2.9200')
Python 2.7.5
Windows: ('8', '6.2.9200', '', 'Multiprocessor Free')
Traceback (most recent call last):
File "site-packages\calibre\gui2\add.py", line 42, in add_one
File "site-packages\calibre\db\legacy.py", line 211, in create_book_entry
File "site-packages\calibre\db\cache.py", line 57, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 1390, in create_book_entry
File "site-packages\calibre\db\cache.py", line 1161, in set_metadata
File "site-packages\calibre\db\cache.py", line 984, in update_path
File "site-packages\calibre\db\backend.py", line 1486, in update_path
File "site-packages\calibre\db\tables.py", line 130, in set_path
File "site-packages\calibre\db\backend.py", line 792, 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

I must add that I've changed the ownership of the metadata.db file to my user id and I've also enabled full control over that file so there were no restrictions placed on the operations using that file. I'm also running Calibre as an administrator. However it doesn't help.

Of course I'm familiar with the official restriction related to placed Calibre library over networked drives (as stated here) but since I've been using sumbolic link to the library I was hoping to overcome potential problems (in many cases it helps). Apparently I wasn't right.

Is anyone able to advise me on that?

itimpi · 07-02-2014, 07:38 AM

Use of network drives to store a Calibre library is not officially supported.

Some people seem to manage to get it to work, but others encounter issues. I am not sure if there are clear views of when one can expect it to work.

mbovenka · 07-02-2014, 07:53 AM

Quote:

Originally Posted by itimpi

Use of network drives to store a Calibre library is not officially supported.

Some people seem to manage to get it to work, but others encounter issues. I am not sure if there are clear views of when one can expect it to work.

I'm one of those it seems to work fine for. I run a database check every now and again (including a comparison with the files on disk) and haven't run into any problems yet. But as I haven't done anything special (just dumped the stuff on my NAS and pointed Calibre at it), I also have no idea why it works for me and not for others.

But like you say, the Big Man himself says 'Not supported; on your own head be it!', so if the OP has issues with it, well, 'don't do that, then'

mikolajek · 07-02-2014, 08:38 AM

Well, I have done a lot of "special"

trying to cheat Calibre that its database is located on a local drive but I've apparently failed. The reason of my question was exactly what itimpi said - for some of forum member it somehow works. I wish I was one of them.

What I most likely do is copy my Calibre collection on a local drive and set up a sync mechanism to have an exact copy on my NAS server for security purposes.

mbovenka · 07-02-2014, 10:48 AM

Quote:

Originally Posted by mikolajek

What I most likely do is copy my Calibre collection on a local drive and set up a sync mechanism to have an exact copy on my NAS server for security purposes.

Yep, that's the safest way to go, then. I use FreeFileSync for that.

Ackis · 07-11-2014, 11:49 AM

What type of network share are you using?

I'm going to assume Linux, which means you probably are using Samba? If that's the case make sure you check the Linux file system permissions AND Samba permissions. although this may not apply because you're probably using the standard NAS software.

Adoby · 07-13-2014, 04:11 AM

I had my calibre library on a NAS share for several years. I didn't have to do anything special, just moved the library and used it. I used NFS to share, no SMB or CIFS. Synology NAS and Ubuntu Linux on the PC. It worked fine, if a bit slow. Now I have the library on a bigger local drive, and backup to the NAS using BackInTime.

I assume that it is SMB and CIFS that causes problems.

itimpi · 07-13-2014, 06:01 AM

Quote:

Originally Posted by Adoby

I had my calibre library on a NAS share for several years. I didn't have to do anything special, just moved the library and used it. I used NFS to share, no SMB or CIFS. Synology NAS and Ubuntu Linux on the PC. It worked fine, if a bit slow. Now I have the library on a bigger local drive, and backup to the NAS using BackInTime.

I assume that it is SMB and CIFS that causes problems.

I do not think it is as simple as that. I have been successfully working with the library on an unRAID box with SMB access and Windows client. On Windows I have Calibre and the files it uses set to be excluded from virus checking. I also normally use the option in Calibre to explicitly set the database location to be local as that vastly improves performance, but it works OK without that.

It seems very hit-and-miss as to whether it will work for any combination of NAS and client and protocol. I think there are other factors such as your virus/internet security software and the setting you use that can come into play as well.

darryl · 07-13-2014, 09:18 AM

Calibre running on just about any version of Windows seems to work fine using a samba share over an nfs file system. Linux clients will not work unless you disable oplocks on mounting the share. I think the option is something like --nobrl but you will need to check this. No matter what OS you use, it is also very important to make sure your share is not accessed simultaneously by more then one machine, as this can lead to corruption.

Remember, Kovid does not recommend or support this for a reason. Use this at your own responsibility.

07-13-2014, 04:11 AM	#7
Adoby Handy Elephant Posts: 1,737 Karma: 26785684 Join Date: Dec 2009 Location: Southern Sweden, far out in the quiet woods Device: Samsung Galaxy Tab S8 Ultra	I had my calibre library on a NAS share for several years. I didn't have to do anything special, just moved the library and used it. I used NFS to share, no SMB or CIFS. Synology NAS and Ubuntu Linux on the PC. It worked fine, if a bit slow. Now I have the library on a bigger local drive, and backup to the NAS using BackInTime. I assume that it is SMB and CIFS that causes problems. Last edited by Adoby; 07-13-2014 at 04:13 AM.

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07-02-2014, 07:38 AM	#2
itimpi Wizard Posts: 4,553 Karma: 950151 Join Date: Nov 2008 Device: Sony PRS-950, iphone/ipad (Marvin/iBooks/QuickReader)	Use of network drives to store a Calibre library is not officially supported. Some people seem to manage to get it to work, but others encounter issues. I am not sure if there are clear views of when one can expect it to work.

07-02-2014, 08:38 AM	#4
mikolajek Junior Member Posts: 5 Karma: 10 Join Date: Jun 2013 Location: Warsaw, Poland Device: Kindle PaperWhite IV	Well, I have done a lot of "special" trying to cheat Calibre that its database is located on a local drive but I've apparently failed. The reason of my question was exactly what itimpi said - for some of forum member it somehow works. I wish I was one of them. What I most likely do is copy my Calibre collection on a local drive and set up a sync mechanism to have an exact copy on my NAS server for security purposes.

07-11-2014, 11:49 AM	#6
Ackis Member Posts: 21 Karma: 10 Join Date: Sep 2013 Location: Canada Device: Galaxy Tab 2 10.1, iPad 2	What type of network share are you using? I'm going to assume Linux, which means you probably are using Samba? If that's the case make sure you check the Linux file system permissions AND Samba permissions. although this may not apply because you're probably using the standard NAS software.

07-13-2014, 09:18 AM	#9
darryl Wizard Posts: 3,108 Karma: 60231510 Join Date: Nov 2011 Location: Australia Device: Kobo Aura H2O, Kindle Oasis, Huwei Ascend Mate 7	Calibre running on just about any version of Windows seems to work fine using a samba share over an nfs file system. Linux clients will not work unless you disable oplocks on mounting the share. I think the option is something like --nobrl but you will need to check this. No matter what OS you use, it is also very important to make sure your share is not accessed simultaneously by more then one machine, as this can lead to corruption. Remember, Kovid does not recommend or support this for a reason. Use this at your own responsibility.