Troubleshooting Help with Kindle Oasis mounting as read-only after a while - no thumbnails

[Celegit]

Hello, everyone,

I am writing here because I am cyclically having problems with my Kindle Oasis version 2019 (10th generation). The problem that occurs is this: the Amazon_cover_bug folder created by Calibre, which is supposed to contain the thumbnail files of the images are sometimes not created, and are not copied to the "secret" folder 'thumbnails'

. Unplugging and plugging the kindle with calibre active doesn't help either, for two reasons: firstly, because I always have the aeroplane mode active; and secondly, because the kindle is apparently loaded in 'Read Only' mode. This happens on two different computers, one with windows 10, the other with windows 11. The firmware is the latest available: 5.16.9.

To get around this problem, I have to restart the kindle by leaving it connected to the PC with calibre active: at which point if I load the books through calibre, it manages to generate the covers in the "Amazon_Cover_Bug" folder and the thumbnails appear regularly.

Even this workaround (restarting the kindle before plugging it in and loading the pictures) stops working after a while, because the device is always loaded in read-only mode, 6 or 7 times that I adopt this workaround.

I tried resetting the kindle to factory settings, and for a while it loads them quietly, and the thumbnails are generated. But after a few times, bang, the problem recurs.

Do you have a solution? Otherwise the device works. Thank you very much!

[j.p.s]

I think that you may be having the same problem as the OP in this thread:
https://www.mobileread.com/forums/sh...d.php?t=360052

It turned out that something was corrupting the file system. He traced it to a particular directory and fixed the problem by deleting the directory and its contents. I might be one particular book or a problem in calibe cover generation or a problem in the copying process.

[Celegit]

How can I diagnose the problem? Is there a command to use in a Windows environment?

[j.p.s]

Originally Posted by Celegit

How can I diagnose the problem? Is there a command to use in a Windows environment?

I haven't used microsoft products for decades.

But there have been reports over the years of chkdsk making things worse on kindles. There is probably some GUI equivalent that would have the same problems. Either might indicate where the problem is, but they shouldn't be able to fix anything anyway, since the kindle is mounted readonly.

If the problem file is the book itself, you can delete it from the kindle's UI, but that will leave the .sdr directory behind, which seems to be more likely the source of the problem.

This is something best fixed on a jailbroken kindle, but I assume that is not an option for you.

It looks like reset is your only option. If a particular book causes the problem, you will have to avoid putting it on your kindle except via amazon services.

[Celegit]

Good evening,

I think I managed to solve the problem: your advice proved providential.

I did some tests after rebooting the kindle, specifically:

- I tried saving the files on the hard disk from the Calibre library, saving the entire library and correcting the books that had cover and metadata errors;

- I deleted the *.partial files in the 'thumbnails' folder, a hidden subfolder of system, and deleted two empty folders there.
I think this last step proved decisive, because now the Kindle mounts smoothly, and the covers, with calibre, are generated.

Honestly, I still don't quite understand why every time I unmount and re-mount the kindle in aeroplane mode, these *.partial files are generated. It's not connected to the internet!

Anyway, it works now! Thanks!