Quote:
Originally Posted by Grins
In the “good old days” (until around the end of 2022) it was possible to connect a Kobo reader to calibre (via USB cable) and copy / save 200 or more books or documents (all in EPUB format) onto the reader with single file transfer. It was even possible to have 500 document saved with a single file transfer.
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The last batch of files I sent from my computer to a Kobo Sage was 4500 epubs. Note that these epubs are all error checked with epubcheck. I also have sent ~13,000 epubs to a Clara HD (internal storage updated to 128GB) and while importing them took quite a while, no other issues were seen.
Quote:
Originally Posted by Grins
However, the software updates in 2023 made this impossible - worse, there were database errors on the readers, which even led to the complete inoperability of at least 2 devices.
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I've seen the database issues however they have nothing to do with the number of books sent in one batch and, as far as I can tell, are due to the database not being properly closed before the USB connection is established. You will see the BookReader.sqlite and/or the KoboReader.sqlite file will have their <databasename>.sqlite-wal and <databasename>.sqlite-shm files still present if you look at the contents of the .kobo directory.
On my Sage, I do use a reboot option in NickelMenu to ensure the database is closed before connecting to my computer.
I am rather surprised that you would state a database error would result in complete inoperability. At the worst, database corruption would require a factory reset.
Quote:
Originally Posted by Grins
Since then I have been using Pocketbook devices (in the manner described above) and have no longer had any problems.
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Personally, I find Pocketbook devices to be limiting in their metadata management.
Quote:
Originally Posted by Grins
This thread is not about whether 500 "real" books or documents can be read in a short time (that's not the application here, by the way), but about the stability of the device software.
Now a student of mine wants to use his reader in a similar way as me. He owns a Kobo Clara 2E. Given my experiences, I advised him against it, but he "loves" his Kobo 
Therefore my questions: How do you copy EPUB documents from calibre to the Kobo reader via file transfer? Which of the 3 “device interface plugins” do you use? How many books do you copy onto the reading device at a single time? If you divide 500 documents into smaller quantities, how large are these quantities? Do you switch off the device completely once the file transfer and database update has been successful so that the database can completely rebuild itself? |
There are only two device interface plugins for Kobo Touch devices. The Kobo Touch driver which comes builtin to calibre and the Kobo Touch Extended driver which is an optional addon and is only useful if you want to convert from epub to kepub on the fly.
As mentioned above, I sent ~13K epubs to my Clara HD in one pass and saw no issues. I don't switch off the device though that does not trigger a database rebuild, it would simply ensure that the database on disk and in RAM copies will be synchronized.
I did run into issues when importing books whether 500 or a single book when I first started using calibre however since I started error checking books as they are added into my calibre library, I haven't seen import issues in quite a few years.