Two installations using the same bookstore

victor50 · 01-29-2021, 10:45 AM

Because of the DRM problem I decided to downgrade my Calibre to 4.x and to install a 5.x version on my PC on another location, using the same bookstore location on my NAS. The two locations are connected by VPN and the same networkdrive is available on both locations. Still when installing the 5.x version didn't "see" the books installed. I could add books that are not seen on the other location. Now, the DRM issue seems to be resolved, so I installed the newest 5.10 (64) on both locations. Still no joy. I could add the two new books by draging the epubs to the masterlist, but that was it. The metadata is set to the bookstore on the NAS. There is only one metadata.db.
Now on the original location there also is a books.db that is actually loaded. On both locations there is a setting "database_path": "C:\\Users\\name/library1.db".
However on the new location there is no books.db! I copied the books.db to the new location, but it doesn't load. I would like to have this books.db in the library so the same database can be used by both installations.

Then on the new location there is an option Books > Export/Import calibre data.
There is no such option on the old location.

I think I will switch to a browserversion on the new location, when the serverside is stable. Still this is all very odd.

aborel · 01-30-2021, 04:10 AM

Quote:

Originally Posted by victor50

Because of the DRM problem I decided to downgrade my Calibre to 4.x and to install a 5.x version on my PC on another location, using the same bookstore location on my NAS. The two locations are connected by VPN and the same networkdrive is available on both locations. Still when installing the 5.x version didn't "see" the books installed. I could add books that are not seen on the other location. Now, the DRM issue seems to be resolved, so I installed the newest 5.10 (64) on both locations. Still no joy. I could add the two new books by draging the epubs to the masterlist, but that was it. The metadata is set to the bookstore on the NAS. There is only one metadata.db.

The official documentation, and many practical cases along the years, indicate that this is a Bad Idea™ https://manual.calibre-ebook.com/faq...rked-drive-nas

You should get the Calibre database back to a non-networking drive before some corruption happens.

JSWolf · 01-30-2021, 05:52 AM

Quote:

Originally Posted by aborel

You should get the Calibre database back to a non-networking drive before some corruption happens.

Sounds like some corruption has already happened.

victor50 · 02-04-2021, 02:46 AM

There are two databases: books.db and metadata.db, the first one is stored in the userprofile and the location is stored there too in global.py.json Haven't tried to relocate. The second one can be relocated in the interface and is on my NAS where the books are stored. This has been working for years and they are not corrupted. My guess as a programmer is that the metadata is accessed via books.db. So the problem is that I can't find any (local) books.db on the second computer. Copying the books.db to the proper location on the second computer doesn't do anything.

BetterRed · 02-04-2021, 03:26 AM

Quote:

Originally Posted by victor50

There are two databases: books.db and metadata.db, the first one is stored in the userprofile and the location is stored there too in global.py.json Haven't tried to relocate. The second one can be relocated in the interface and is on my NAS where the books are stored. This has been working for years and they are not corrupted. My guess as a programmer is that the metadata is accessed via books.db. So the problem is that I can't find any (local) books.db on the second computer. Copying the books.db to the proper location on the second computer doesn't do anything.

AFAIK books.db is not a calibre artefact. Does its schema resemble metadata.db, which is calibre's SQLite database. What are the file modification dates of the two .db files.

BR

victor50 · 02-04-2021, 03:55 AM

books.db is half the size of metadata.db. However metadata.db is not visible as opened in Process Explorer while books.db is. Maybe it is closed when info has been obtained. Both have recent dates of change. books.db resides in the .\appdata\roaming\Calibre folder. Can't see the other Calibre setup from here, but as said it isn't in the folder and isn't loaded. I guess I will need a tool for analyzing the schemes. Don't have time for that.

kovidgoyal · 02-04-2021, 03:58 AM

books.db is not used or even created by calibre.

victor50 · 02-04-2021, 04:29 AM

I wonder about this... (see screenshot)

kovidgoyal · 02-04-2021, 05:33 AM

it will have been created by some third party plugin you are using run calibre as

calibre --ignore-plugins

victor50 · 02-08-2021, 06:34 AM

Problem solved. Books.db turned out to be the calibre.db after all. It was set a long time ago with CALIBRE_OVERRIDE_DATABASE_PATH. I removed the override and copied and renamed books.db to the NAS-folder. Now I can use Calibre on both PC's, even at the same time. With the Calibre webclient I can only see book title and author. All other meta seems hidden. Then I have to download it, while I want to use the book on its location on the NAS so highlights etc are preserved. Unfortunately this seems not possible while using FBReader on my phone.

chaley · 02-08-2021, 06:52 AM

Quote:

Originally Posted by victor50

I removed the override and copied and renamed books.db to the NAS-folder. Now I can use Calibre on both PC's, even at the same time.

Accessing a calibre library from two instances of calibre will destroy your calibre database. I really mean "will", not "might".

Quoth · 02-08-2021, 07:57 AM

The only safe way to use Calibre on more than one PC might be to store it on a local USB drive. I'm not sure. A network drive or NAS even for one user at a time is a bad idea. A networked database used by more than one user / application program at the same time when it's single user like Calibre is a total disaster waiting to happen. You need a remote database server that's multiuser (Maria, MySQL, MSDE, MS-SQL, Oracle, DB2 etc, not SQLight, Access or similar set of files accessed directly by the application, and the application has to be somewhat aware. AFAIK Calibre doesn't support a database server API, it's single user and assumes total exclusive access to local files.

victor50 · 02-08-2021, 11:20 AM

Quote:

Originally Posted by chaley

Accessing a calibre library from two instances of calibre will destroy your calibre database. I really mean "will", not "might".

I just added two books, converted them to EPUB and edited metadata, while on the other PC Calibre was open (and in server-mode). Database functions perfectly. The only thing is that it didn't refresh and there wasn't a possibility to force a refresh. After restart it did show the added books ok. Then, I think in the helpfile topic "CALIBRE_OVERRIDE_DATABASE_PATH" it says this is usefull when the external drive doesn't support locking, meaning that multiuser use is possible. Maybe @kovidgoyal could shed some more light on the matter

theducks · 02-08-2021, 11:28 AM

Why are you arguing with the Creator and one of the core code developers?

Locking has Internal (to app) uses and does NOT imply Multiple uses.

victor50 · 02-08-2021, 11:33 AM

Quote:

Originally Posted by theducks

Why are you arguing with the Creator and one of the core code developers? Locking has Internal (to app) uses and does NOT imply Multiple uses.

I didn't argue with the creator AFAIK. And posting facts can't be a problem I hope? Especially when someone says the database will be destroyed, when it isn't.

01-29-2021, 10:45 AM	#1
victor50 Member Posts: 14 Karma: 10 Join Date: Sep 2014 Device: PC W10pro, Android Moto 5S	Two installations using the same bookstore Because of the DRM problem I decided to downgrade my Calibre to 4.x and to install a 5.x version on my PC on another location, using the same bookstore location on my NAS. The two locations are connected by VPN and the same networkdrive is available on both locations. Still when installing the 5.x version didn't "see" the books installed. I could add books that are not seen on the other location. Now, the DRM issue seems to be resolved, so I installed the newest 5.10 (64) on both locations. Still no joy. I could add the two new books by draging the epubs to the masterlist, but that was it. The metadata is set to the bookstore on the NAS. There is only one metadata.db. Now on the original location there also is a books.db that is actually loaded. On both locations there is a setting "database_path": "C:\\Users\\name/library1.db". However on the new location there is no books.db! I copied the books.db to the new location, but it doesn't load. I would like to have this books.db in the library so the same database can be used by both installations. Then on the new location there is an option Books > Export/Import calibre data. There is no such option on the old location. I think I will switch to a browserversion on the new location, when the serverside is stable. Still this is all very odd.

02-04-2021, 04:29 AM	#8
victor50 Member Posts: 14 Karma: 10 Join Date: Sep 2014 Device: PC W10pro, Android Moto 5S	I wonder about this... (see screenshot) Attached Thumbnails

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02-04-2021, 02:46 AM	#4
victor50 Member Posts: 14 Karma: 10 Join Date: Sep 2014 Device: PC W10pro, Android Moto 5S	There are two databases: books.db and metadata.db, the first one is stored in the userprofile and the location is stored there too in global.py.json Haven't tried to relocate. The second one can be relocated in the interface and is on my NAS where the books are stored. This has been working for years and they are not corrupted. My guess as a programmer is that the metadata is accessed via books.db. So the problem is that I can't find any (local) books.db on the second computer. Copying the books.db to the proper location on the second computer doesn't do anything.

02-04-2021, 03:55 AM	#6
victor50 Member Posts: 14 Karma: 10 Join Date: Sep 2014 Device: PC W10pro, Android Moto 5S	books.db is half the size of metadata.db. However metadata.db is not visible as opened in Process Explorer while books.db is. Maybe it is closed when info has been obtained. Both have recent dates of change. books.db resides in the .\appdata\roaming\Calibre folder. Can't see the other Calibre setup from here, but as said it isn't in the folder and isn't loaded. I guess I will need a tool for analyzing the schemes. Don't have time for that.

02-04-2021, 03:58 AM	#7
kovidgoyal creator of calibre Posts: 45,359 Karma: 27182818 Join Date: Oct 2006 Location: Mumbai, India Device: Various	books.db is not used or even created by calibre.

02-04-2021, 05:33 AM	#9
kovidgoyal creator of calibre Posts: 45,359 Karma: 27182818 Join Date: Oct 2006 Location: Mumbai, India Device: Various	it will have been created by some third party plugin you are using run calibre as calibre --ignore-plugins

02-08-2021, 06:34 AM	#10
victor50 Member Posts: 14 Karma: 10 Join Date: Sep 2014 Device: PC W10pro, Android Moto 5S	Problem solved. Books.db turned out to be the calibre.db after all. It was set a long time ago with CALIBRE_OVERRIDE_DATABASE_PATH. I removed the override and copied and renamed books.db to the NAS-folder. Now I can use Calibre on both PC's, even at the same time. With the Calibre webclient I can only see book title and author. All other meta seems hidden. Then I have to download it, while I want to use the book on its location on the NAS so highlights etc are preserved. Unfortunately this seems not possible while using FBReader on my phone.

02-08-2021, 07:57 AM	#12
Quoth Still reading Posts: 14,048 Karma: 105092227 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	The only safe way to use Calibre on more than one PC might be to store it on a local USB drive. I'm not sure. A network drive or NAS even for one user at a time is a bad idea. A networked database used by more than one user / application program at the same time when it's single user like Calibre is a total disaster waiting to happen. You need a remote database server that's multiuser (Maria, MySQL, MSDE, MS-SQL, Oracle, DB2 etc, not SQLight, Access or similar set of files accessed directly by the application, and the application has to be somewhat aware. AFAIK Calibre doesn't support a database server API, it's single user and assumes total exclusive access to local files.

02-08-2021, 11:28 AM	#14
theducks Well trained by Cats Posts: 31,062 Karma: 60358908 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Why are you arguing with the Creator and one of the core code developers? Locking has Internal (to app) uses and does NOT imply Multiple uses.