Direct copying of epub files on the Kobo internal file system

Question

I am running Linux (Mageia 5), and I own a Kobo Glo HD. There is no Kobo Desktop for me (that I know of). I wish to load some free epub books on my reader.

I read in several places that one can copy epub book files directly on the Kobo file system. What I understood is that one can connect the Kobo with a USB cable so that it appears to the PC as a USB drive, on which files can be copied directly by the PC.

Indeed I can connect my Kobo to the Linux PC, and then by mounting /dev/sdc (usually, but not /dev/sdc1) on some directory, (some of ?) the content of the Kobo reader becomes accessible as a 3.2GB file system.

Following the suggestion of Sekhemty's answer to another question, I did create a directory at the top-level of this file system, and included some epub files in this directory and in a subdirectory, using various formats for file names, just in case. None of it was seen by my Kobo reader.

My guess is that the files have to be put in a specific place, but I did not dare start disturbing too much the file system without knowing what I was doing.

So my question is: what are the constraints to be respected when adding new ebooks in the Kobo file system, i.e. in particular:

• where in the file system should they be copied ?

• are there constraints on the file (or directory) names to be used ? Is the suffix .epub needed ?

• are there other constraints I did not think of ?

• should I do something on the Kobo reader after I disconnect, so that the new epub files are taken into account?

I am aware that the simpler solution is to do it with existing software like Calibre, but I am a bit short on time and right now I have a problem getting Calibre detecting that my Kobo reader is connected. Actually I am not sure what connected means in the e-reader jargon ... I am interpreting it as mounted, but I am not sure.

Added a day later: I tried to copy epub files or directories containing epub files in various places on my kobo reader. They were ignored. In particular I tried the only directory already containg epub files which is KOBOeReader/.kobo/kepub/ where KOBOeReader is the directory the Kobo file system is mounted on. No success at all.

Answer 1

In a nutshell

One way to make visible epub files copied directly on the Kobo file system is to use the Kobo browser once afterwards to download an epub file from the web.

Context

I did some more experimenting on my own, and finally succeeded, though I did not explore the precise boundaries of what can work and what will not work. I am giving details, so that you know my experimental evidence. This is personnal experiment, not anything I read anywhere. So, get second confirmation if that info is critical for your purpose.

If you are only interested in the result, and the technique to transfer ebooks to your Kobo without any specific software, simply jump to the last section od this answer.

My question was motivated by the fact that I wanted to transfer ebooks from my Linux computer to my Kobo eReader. I am running Calibre, which I use to improve some of the ebooks, but for some reason that I have not yet identified, it will not detect my Kobo when it is connected to the computer by a USB cable.

So having read in various places that a Kobo can be seen as a USB drive, on which ebooks can be copied, I tried as reported above without success, but no indication of the reason(s) for failure. The files were simply ignored, wherever I put them. Performing a sync did not help.

The experiments

Then serendipity came to my help. I had been wondering for some time how I could connect to book sources on the web. I did not know how to browse the web with the Kobo. And then I discovered the hidden web browser, which they consider experimental. In Kobo's own words:

Since the browser is still a beta feature, some websites may not display properly. Please note that the browser is not officially supported by Kobo.

Indeed, there is no indication in their user guide (which I had read) of the very exixtence of that browser, and I had to search the web on my computer to find it. Then I found the help page that explains how to activate this browser.

So I tried the Kobo browser to download a (DRM-)free book from the web. It worked ... and (nearly) all the books I had copied by hand on the Kobo file system became visible and readable. I am saying nearly all, because it actually saw only the files with an .epub suffix. Those files had been copied

• directly in the root directory of the Kobo file system,

• or in a directory codex I had created at the root of the Kobo file system,

• or in a subdirectory of that codex directory.

I did not check how deep the hierarchy can be.

Note that the book I downloaded from the web was also stored by the Kobo eReader browser in the root directory. However, books with DRM are clearly stored somewhere else.

I did not (dare to) check what happens when a file has a .epub suffix, but is not an epub file. But I did check that ebooks placed in other locations are not seen (of course, I checked only some locations), unless it is a user created directory hierarchy placed in the root directory.

I added some more books to check for other means to make then visible to the user. Since downloading a book seemed critical, I was wondering whether a sync induced download would do the job (it does not). Then I added two Kobo (DRM-)free books to my account on Kobobooks.com, and checked in my computer that they were indeed added to my account on kobobooks.com.

Then I performed a sync on my Kobo, and it did download the two books. But that did not make visible the books I had previously added directly in the file system. It is worth noting that, though they were (DRM-)free, these ebooks were not downloaded at the root of the file system, like the epub files downloaded by the browser.

But when I downloaded an ebook from project Gutenberg, the new books I had copied directly in the file system became visible in the book collection of the Kobo eReader.

This is already longer than it should. So, I am skipping some details to give my conclusions, for what I understand.

Some basic know-how for adding (DRM-)free ebooks directly to the Kobo memory.

The key idea is that the Kobo eReader (or at least the Kobo Glo HD that I use - but I suspect several of them work the same) has a web browser, which can be used to download books in your Kobo.

The browser is somewhat hidden, as Kobo considers it an experimental item, not officially supported.

The browser download the epub files right in the root directory. And then calls some piece of software to integrate it into its organization of the ebooks collection. The nice point is that it checks all the non-standard (i.e. non system) files and directories that are present at the root level, so as to recreate the information needed to integrate them. Aa a result, it takes into account the fact that some files may have been removed, modified or moved into a different subdirectory.

The only bad news is that (afaik) the only way to get that software executed is to download an epub file from some site with the Kobo browser.

Hence, copying ebooks from your computer onto the Kobo, assuming the computer does not have a web server, can be achieved by connecting the Kobo to the computer with a USB cable. The Kobo is then seen as a memory device, with a file system which can be mounted as usual (for example on directory /mnt with : mount /dev/sdc /mnt depending on where it shows up, here on /dev/sdc -- note that it is not /dev/sdc1). Then you can copy epub files or file hierarchies at the root /mnt of this file system. Then you dismount the file system with umount /mnt, and make sure copying is terminated (Unix sync command) before removing the USB cable, if you will. Finally, you use the Kobo browser to download at least one extra ebook (possibly always the same one :-).

This was described for a Linux system, but should be adaptable to any operating system.

An important point is that all the epub files must have the .epub suffix.

Another thing that I have not been able to determine is whether these files can benefit from other services, such as cloud storage. But I am very moderately interested in the cloud anyway.

Now, some other user may have better, simpler ways of achieving the same result, or more, without using specific software such as Calibre. I find it a bit frustating not to be able to used Calibre because it will not detect the Kobo USB connection on my machine. I would not mind using a degraded version where I would have to tell Calibre when the Kobo is connected and where.

Answer 2

some older versions of Calibre use a legacy Kobo driver. most distros aren't up-to-date as Calibre is developed quite extensively and often.

I suggest installing Calibre from the developer's site. I owned a Kobo Aura, and the version of Calibre that Ubuntu shipped at the time failed me... I installed from the site, and problem solved. good luck.

https://calibre-ebook.com/download_linux

Answer 3

It's years since I owned a Kobo. But the easiest way to get books onto a Kobo from your computer is to install Calibre. As soon as you connect your Kobo, calibre will recognize it, and you can sideload epubs to your heart's content.

Answer 4

On the Kobo Arc you copy your books to the reader just like you would to a usb stick, then on the reader go to the home page. In the top left corner you have the menu icon which you press on then select 'my books'. On the next screen you click on the little column of dots in the top right corner for the menu and then import content. That will add any compatible books you have copied to the memory of the device from your pc and give you the option of deleting the original files once imported to the right place on the reader.

Answer 5

I have a Kobo Aura H2O. Here are directions for Windows. This works for me under Windows 8 and Windows 10.

• Connect the Kobo to your PC using a USB cable. The Kobo will appear as another drive letter under Windows.
• Go to the Kobo drive. In the root directory, look for a folder called contents. (Could be content, I don't have the kobo with me.) If contents doesn't exist, make it. I had to do this with my brand new Kobo.
• Drag all EPUB files to the Kobo contents folder.
• In Windows, right click the Kobo drive and choose "disconnect". You can also go to the System tray, right click the USB symbol, and click "eject Kobo" or whatever name Windows gave to the Kobo.
• Unhook the USB cable from the Kobo. It should reboot and import all books in that contents directory and they should appear on your Home screen in Kobo.