Calibre Cover Options

[andhistablet]

Hi all. I have a large amount of ebooks in Calibre (over 10,000) and I have tried moving a large chunk of them to my Kindle Oasis. When I attempt to transfer as one job, the program crashes, and several popups have mentioned a memory error. If I try to do a large batch (1,000 for example), the Kindle crashes Calibre when trying to reconnect and read Kindle metadata. When "Getting Books from Device," Calibre crashes and closes at around the 90% mark.

As a result, I move my books in batches of ~100 and it seems to work okay. However, once on the device, not all of them have covers. I am well aware of the cover bug and the need to disconnect/reconnect to Calibre to restore lost covers, but my issue is that they never transfer in the first place and definitely not restored on a reconnect. If I am doing only one book at a time, there is no issue, but the batches of 100 largely do not show covers, while some of them do. My questions:

1. Is there a list of parameters or signs as to why certain books would or would not show covers? Perhaps a published list of best "practices?" Or maybe a limit of book transfers per job?

2. Obviously I have a large number of books on my device. Is there any way to send cover metadata to the device again barring a removal + new transfer of ALL my files?

3. Any options I may not have tried?

Any thoughts are welcome as I am out of ideas and have even reset my kindle to factory settings once while trying to find solutions. Running Calibre 5.42. Thank you in advance!

[DNSB]

Couple of quick questions.

What OS are you running calibre under? If Windows 64 bit are you using the 64 bit version of calibre?

Are you converting the books on the fly or are they all in mobi/KF8/KFX format in your library?

If KF8, if you open one of them in calibre's ebook-editor, does the error check show any errors?

Edit: You might also want to take a look at HarryT's Tips for loading a large library onto a KO2 thread. A bit old but most of it still applies especially the indexing wait times.

[andhistablet]

Thank you David for looking into this. I am using Windows 10 64-bit, and I thought I was using Calibre 64-bit, but I was not. I just installed 64-bit.

All of my books have already been converted to AZW3 prior to transfer, and that format is what I am sending to Kindle. Should I convert to KF8 or KFX as well?

Thanks again, and I will look at HarryT's thread now.

[DNSB]

Originally Posted by andhistablet

Thank you David for looking into this. I am using Windows 10 64-bit, and I thought I was using Calibre 64-bit, but I was not. I just installed 64-bit.

All of my books have already been converted to AZW3 prior to transfer, and that format is what I am sending to Kindle. Should I convert to KF8 or KFX as well?

Thanks again, and I will look at HarryT's thread now.

AZW3 is calibre's filetype for KF8 so no need to do another conversion.

There have been several threads in which the original poster (OP in future) had a 32 bit version of calibre installed on a 64 bit version of Windows and was running into memory exhaustion. Changing to the 64 bit version of calibre helped in enough cases that it's almost a reflex to check that possibility.