Calibre rescans entire SD card each time device is connected

[michaelmcd]

I have a Boyue Likebook Mars with an external SD card on which I store the books that I load from Calibre. I've noticed this odd behavior from Calibre where it rescans the whole file system on the card each time I connect the device, taking anywhere from 10 to 25 minutes.

Calibre is on version 4.13 running on Ubuntu Linux, I've fiddled with the different options for metadata management and configured the device and SD card to scan only specific folders, but each connection still involves a full scan (at least, going by the "Found object <folder>" messages that show up for the fetching book list task in the jobs window).

Is there anything I can do to speed up this process?

[theducks]

DON'T remove the 2 files Calibre writes into the root of each storage medium.
Those are the scan results and matching device ID - Library link.

Those scan must complete and the resultant files written or it start all over

[kovidgoyal]

Is this an MTP device?

[michaelmcd]

Originally Posted by theducks

DON'T remove the 2 files Calibre writes into the root of each storage medium.
Those are the scan results and matching device ID - Library link.

Those scan must complete and the resultant files written or it start all over

I had let it run to completion initially but that didn't seem to help. For fun this afternoon, I tried removing the Calibre metadata files, connecting the device, allowing Calibre to scan to completion, manually sent metadata from the device menu, ejected through Calibre and reconnected the device and it still began a full scan of the SD card.

[michaelmcd]

Originally Posted by kovidgoyal

Is this an MTP device?

Yes. I restarted Calibre in debug mode and connected the device and the messages around scanning are mostly prefixed with "MTP: ".

[kovidgoyal]

If you've configured it to scan only particular folders, I dont see how it would be scanning them all. Does this happen only on the SD card or the main memory as well?

[michaelmcd]

Originally Posted by kovidgoyal

If you've configured it to scan only particular folders, I dont see how it would be scanning them all. Does this happen only on the SD card or the main memory as well?

It appears to only be the SD card, based on the directory names shown in the jobs window. The debugging log writes out that some of the other main directories are excluded, but the entire ebooks directory is definitely rescanned.

[stumped]

Originally Posted by michaelmcd

It appears to only be the SD card, based on the directory names shown in the jobs window. The debugging log writes out that some of the other main directories are excluded, but the entire ebooks directory is definitely rescanned.

probably because calibre does not have write permission for the SD card, so it cannot place the necessary 2 scan results files there ?

[kovidgoyal]

could be a bug I dont have an mtp devices that support sd cards to test with though.

[gbm]

Originally Posted by michaelmcd

It appears to only be the SD card, based on the directory names shown in the jobs window. The debugging log writes out that some of the other main directories are excluded, but the entire ebooks directory is definitely rescanned.

I have a couple of suggestions.

First run fsck on the sd card.

see for how to do:
https://manual.calibre-ebook.com/faq...-connect-to-it

if that does not fix then reformat the sd card using the reader.

last try a different sd card.

bernie

[MRC01]

I have the same issue. It's a glitch in the way Calibre works.
Calibre won't let you configure which directories to scan for any MTP device, unless that device is plugged in.
When you plug in the device, Calibre immediately kicks off a full scan of the device. This may take more than an hour.
While that full scan is running, you can't configure Calibre.
Catch-22!

So, the only way I can see to do this is:
1. Plug in the device
2. Calibre will detect it and kick off a full device scan job.
3. Be patient and let the job complete (minutes to hours).
4. When the job completes, leave the device plugged in.
5. Use Configure, Plugins, Device, MTP to set which directories to scan

Once you've done the above the first time, it should be fast the next time.

[Quoth]

Originally Posted by MRC01

I
So, the only way I can see to do this is:
1. Plug in the device
2. Calibre will detect it and kick off a full device scan job.
3. Be patient and let the job complete (minutes to hours).
4. When the job completes, leave the device plugged in.
5. Use Configure, Plugins, Device, MTP to set which directories to scan

Once you've done the above the first time, it should be fast the next time.

Yes. I have a Mars and like most Android it's the horrid MTP. It's working OK with Calibre once the first scan is done and the directory is picked. Now faster than File manager. I run Linux Mint with a Mate Desktop and Caja file manager, so I have to stop gvfs-mtp-volume-monitor (not kill or it respawns) or else I ONLY see it in the Filemanager and not in Calibre. Other desktops allow MTP connection in filamanager to be disabled.

I installed KOReader using Mars Browser to Git for ARM apk and installed the APK from Mars Filemanager. KOReader uses the file Calibre creates to do its searches.

My Android Lenovo LCD tablet is also MTP and 256 G SD card rather than 32 G Byte, so first time was a lot worse than the Mars. It is fine now. I use Lithium for ePub and Xodo for PDF on it. I use the supplied ereader on the Mars for PDFs and only use KOReader for epubs.