Restore database does not work correct

JoePass · 03-26-2025, 05:25 PM

Hi,
I use calibre in 4 comps with the same collection. I save collection in GDrive and add new books there. In comps I have locally saved collection and every additional book I download from GDrive (without db and json files). Then I start Restore database and calibre takes all books with new ones. But now in version 8.0.1 it does not work. Calibre does not see new books. What happens?

theducks · 03-26-2025, 06:59 PM

Google Drive modifies file names.
Restore uses metadata.opf found in the books folder for recovery
Files no longer match the one specified in that recovery OPF

There is a FAQ on the help page about NAS and other shared folders

JoePass · 03-27-2025, 01:12 PM

Thank you. Sorry, but I can not find FAQ on the help page. I'm using also Megasync and OneDrive. Does calibre work well with them?

ownedbycats · 03-27-2025, 02:07 PM

No cloud shares. They inevitably break.

slm · 03-27-2025, 02:12 PM

From the comments I've seen, a great many people on MobileRead use Dropbox despite the warnings.
I haven't seen any reports of problems using it nor have I had any problems.
Of course, either Calibre or Dropbox may make a change a some point that breaks things.

DNSB · 03-27-2025, 04:01 PM

Quote:

Originally Posted by JoePass

Thank you. Sorry, but I can not find FAQ on the help page. I'm using also Megasync and OneDrive. Does calibre work well with them?

A quick Google search on 'calibre faq nas' brought me to the calibre page where I found:

I am getting errors with my calibre library on a networked drive/NAS?

Quote:

Originally Posted by slm

From the comments I've seen, a great many people on MobileRead use Dropbox despite the warnings.
I haven't seen any reports of problems using it nor have I had any problems.
Of course, either Calibre or Dropbox may make a change a some point that breaks things.

If I had a nickel for every time I've seen reports from people who have either stored their live library on DropBox or have two-way sync running between their local calibre library and a copy on DropBox and who have ended up with corrupted libraries, I could get a couple of coffees at the local Starbucks. Some of those users got away with doing this for years before it bit them in the butt.

The only safe usage for calibre and cloud/NAS/whatever is either to generate an archive of your calibre library and copy that archive to the cloud. The next choice is to do a one-way sync when calibre isn't running though that will not work with GoogleDrive since the (id number) items after directory names in the calibre library will get replaced/corrupted by GoogleDrive's (version) which makes a calibre library unusable.

BTW, not only have you seen reports, you have responded to them with advice to keep your library on the local drive.

ShellShock · 03-27-2025, 04:02 PM

Yes, I have used DropBox with Calibre for many years. My Calibre library is on a local SSD, which is synched to DropBox storage in the cloud. So Calibre only accesses local files. I access the DropBox cloud from the Mapleread IOS reader app to download ebooks to my IOS devices - always making sure first that Calibre is not running. Because my library is online in the cloud, I can access my ebooks from anywhere and anywhen.

JoePass · 03-28-2025, 12:01 PM

Quote:

Originally Posted by ownedbycats

No cloud shares. They inevitably break.

I'm sure that this function - using clouds, is very important to many users. Is it possible to implement this function? Or may be there is a cloud with which the calibre works?

ownedbycats · 03-28-2025, 02:57 PM

https://manual.calibre-ebook.com/server.html

DNSB · 03-28-2025, 03:00 PM

Quote:

Originally Posted by JoePass

I'm sure that this function - using clouds, is very important to many users. Is it possible to implement this function? Or may be there is a cloud with which the calibre works?

The problem is not with the cloud per se but the network connection required to reach the cloud. See SQLite Over a Network, Caveats and Considerations for more information. One quote from the item:

Quote:

This simple, "remote database" approach is usually not the best way to use a single SQLite database from multiple systems, (even if it appears to "work"), as it often leads to various kinds of trouble and grief. Because these problems are inevitable with some usages, but not frequent or repeatable, it behooves application developers to not rely on early testing success to decide that their remote database use will work as desired.

The database used for calibre could be changed to a client/server database that is designed to function over a network but those come with their own cans of worms and would require a major amount of rewriting calibre's code and that of any plugins that directly access the database.

slm · 03-28-2025, 03:01 PM

The content server is great IF you can access it. Setting it up to be accessed off you local wi-fi network is full of complexities.
Dropbox, on the other hand gives you access to the files without having to expose your home computer as a server.

Sirtel · 03-28-2025, 03:59 PM

Dropbox works quite well, as long as you

access the library only from one device
stop syncing when calibre is open

For accessing your library from multiple computers, calibre content server is the only safe option.

DNSB · 03-28-2025, 04:03 PM

You can always save to disk your library and copy those files to DropBox or do a one-way sync of your library to DropBox when calibre is not running. This discussion seems to be about wanting to use a cloud service to hold the working copy of your library which neither the creators of SQLite or calibre recommend.

To paraphrase the quote I posted in a message above, it'll work until it unexpectedly breaks. That seems to match the number of posts on MobileRead that (again paraphrased) read "I've used my calibre library on <cloud service/NAS/whatever> for years and now calibre says my library is corrupt or can't be opened or whatever other error has happened. HELP!!!"

As for setting up the content server to be accessed outside your local network? That was an easy-peasy task though perhaps decades of working with networks helps there. Compared to the sheer joy of microsegmenting the datacentre and WAN networks to control east-west traffic while allowing the systems to work, it was trivial to allow external secure access to a calibre content server.

rantanplan · 03-28-2025, 04:12 PM

One easy solution could be to run a batch file that uses rclone sync to Dropbox, then starts Calibre and then rclone after that again.

DNSB · 03-28-2025, 11:19 PM

What I've done for a few people is to create a batch file that runs calibre and after calibre exits, runs the sync to DropBox (or other cloud provider). I looked at the sync before opening calibre but decided that since—in theory—the calibre library on the local computer and the cloud provider were synced from the last run, that syncing before starting calibre was not necessary. Also, most people didn't seem to mind a task running for a few minutes after exiting calibre but they were not happy with calibre taking that many minutes to start up.

03-26-2025, 05:25 PM	#1
JoePass Junior Member Posts: 6 Karma: 10 Join Date: Feb 2021 Device: PC	Restore database does not work correct Hi, I use calibre in 4 comps with the same collection. I save collection in GDrive and add new books there. In comps I have locally saved collection and every additional book I download from GDrive (without db and json files). Then I start Restore database and calibre takes all books with new ones. But now in version 8.0.1 it does not work. Calibre does not see new books. What happens?

03-28-2025, 03:59 PM	#12
Sirtel Grand Sorcerer Posts: 13,061 Karma: 237062052 Join Date: Jan 2014 Location: Estonia Device: Kobo Sage & Libra 2	Dropbox works quite well, as long as you access the library only from one device stop syncing when calibre is open For accessing your library from multiple computers, calibre content server is the only safe option.

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03-26-2025, 06:59 PM	#2
theducks Well trained by Cats Posts: 30,880 Karma: 59840450 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Google Drive modifies file names. Restore uses metadata.opf found in the books folder for recovery Files no longer match the one specified in that recovery OPF There is a FAQ on the help page about NAS and other shared folders

03-27-2025, 01:12 PM	#3
JoePass Junior Member Posts: 6 Karma: 10 Join Date: Feb 2021 Device: PC	Thank you. Sorry, but I can not find FAQ on the help page. I'm using also Megasync and OneDrive. Does calibre work well with them?

03-27-2025, 02:07 PM	#4
ownedbycats Custom User Title Posts: 10,585 Karma: 74000001 Join Date: Oct 2018 Location: Canada Device: Kobo Libra H2O, formerly Aura HD	No cloud shares. They inevitably break.

03-27-2025, 02:12 PM	#5
slm Fool Posts: 454 Karma: 4103210 Join Date: Feb 2003 Device: Kindle: Voyage,PW1,KOA, Kobo: Clara Colour, Nook GLP, Pocketbook verse	From the comments I've seen, a great many people on MobileRead use Dropbox despite the warnings. I haven't seen any reports of problems using it nor have I had any problems. Of course, either Calibre or Dropbox may make a change a some point that breaks things.

03-27-2025, 04:02 PM	#7
ShellShock Wizard Posts: 1,178 Karma: 2431850 Join Date: Sep 2008 Device: IPad Mini 2 Retina	Yes, I have used DropBox with Calibre for many years. My Calibre library is on a local SSD, which is synched to DropBox storage in the cloud. So Calibre only accesses local files. I access the DropBox cloud from the Mapleread IOS reader app to download ebooks to my IOS devices - always making sure first that Calibre is not running. Because my library is online in the cloud, I can access my ebooks from anywhere and anywhen.

03-28-2025, 02:57 PM	#9
ownedbycats Custom User Title Posts: 10,585 Karma: 74000001 Join Date: Oct 2018 Location: Canada Device: Kobo Libra H2O, formerly Aura HD	https://manual.calibre-ebook.com/server.html

03-28-2025, 03:01 PM	#11
slm Fool Posts: 454 Karma: 4103210 Join Date: Feb 2003 Device: Kindle: Voyage,PW1,KOA, Kobo: Clara Colour, Nook GLP, Pocketbook verse	The content server is great IF you can access it. Setting it up to be accessed off you local wi-fi network is full of complexities. Dropbox, on the other hand gives you access to the files without having to expose your home computer as a server.

03-28-2025, 04:03 PM	#13
DNSB Bibliophagist Posts: 44,466 Karma: 167726775 Join Date: Jul 2010 Location: Vancouver Device: Kobo Sage, Libra Colour, Lenovo M8 FHD, Paperwhite 4, Tolino epos	You can always save to disk your library and copy those files to DropBox or do a one-way sync of your library to DropBox when calibre is not running. This discussion seems to be about wanting to use a cloud service to hold the working copy of your library which neither the creators of SQLite or calibre recommend. To paraphrase the quote I posted in a message above, it'll work until it unexpectedly breaks. That seems to match the number of posts on MobileRead that (again paraphrased) read "I've used my calibre library on <cloud service/NAS/whatever> for years and now calibre says my library is corrupt or can't be opened or whatever other error has happened. HELP!!!" As for setting up the content server to be accessed outside your local network? That was an easy-peasy task though perhaps decades of working with networks helps there. Compared to the sheer joy of microsegmenting the datacentre and WAN networks to control east-west traffic while allowing the systems to work, it was trivial to allow external secure access to a calibre content server.

03-28-2025, 04:12 PM	#14
rantanplan Weirdo Posts: 811 Karma: 11003000 Join Date: Nov 2019 Location: Wuppertal, Germany Device: Tolino Shine Color, Tolino Vision 6, Kobo Clara 2E, Boox Note Air 2+	One easy solution could be to run a batch file that uses rclone sync to Dropbox, then starts Calibre and then rclone after that again.

03-28-2025, 11:19 PM	#15
DNSB Bibliophagist Posts: 44,466 Karma: 167726775 Join Date: Jul 2010 Location: Vancouver Device: Kobo Sage, Libra Colour, Lenovo M8 FHD, Paperwhite 4, Tolino epos	What I've done for a few people is to create a batch file that runs calibre and after calibre exits, runs the sync to DropBox (or other cloud provider). I looked at the sync before opening calibre but decided that since—in theory—the calibre library on the local computer and the cloud provider were synced from the last run, that syncing before starting calibre was not necessary. Also, most people didn't seem to mind a task running for a few minutes after exiting calibre but they were not happy with calibre taking that many minutes to start up.

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