How to backup your Kobo on a Mac

I backup my Kobo for two reasons: 1) Peace of mind and 2) Creating a clean backup before experimenting with third party scripts & apps. The Kobo only mounts the KOBOEREADER partition, but there are two hidden Linux partitions as well. We'll need to use Terminal to back up the entire disk. The Disk Utility app doesn't see the hidden Kobo partitions.

1) Open a Terminal shell (/Applications/Utilities/Terminal.app) and type the following, then hit "return":

Look to see which disk number is assigned to KOBOEREADER just above and to the left of its name. It might look like /dev/disk4. From now on, I will refer to it as diskX, with "X" representing the drive number your Mac gave to your Kobo.

2) Next, we need to unmount the Kobo through the Terminal, not eject it. Type the following, then hit "return":

If it is successful, you will see the following message:

3) Now we are ready to create a backup disk image of your Kobo's entire SD card. Think of where you want to store your backup disk image and what you'd like to call it. Type the following, BUT DO NOT HIT "return" YET:

In the Finder, drag and drop the folder of where you want the disk image to be stored to the Terminal window. It's Unix path will be autofilled in for you. Then type the name at the end of the path, leaving no spaces between the "/" and your filename. Mine looked like this:

(Wondering what this does? "sudo" means "super user do", and it will prompt you for your password, then give "dd" full access to the entire Kobo volume. "dd" means "Data Definition", and it's a geeky reference to an old IBM command. Basically, it clones your Kobo volume exactly—even the unused space. "if" means "input file" and "of" means "output file".)

Now hit "return". You will be prompted for your password. Once it is accepted, go catch a movie. This will take quite some time as it is making an exact copy of your Kobo's SD card bit by bit, including the two hidden Linux partitions. dd doesn't give any feedback, unfortunately, but expect 2-4 hours.

(There is a way to get dd to give you progress updates, but it requires homebrewing your Mac, which is outside the scope of this tutorial. If there's interest, I'll post more details in a comment.)

Once dd does its thing, you can safely detach your Kobo from your Mac (because it's already unmounted). You now have an exact duplicate of your Kobo on your Mac. With compression, my 128GB SD card created a 127.3GB disk image. The larger the SD card on your Kobo, the longer this process will take. It's slow, but extremely thorough. Double clicking on the disk image will mount it as if it is your actual Kobo. To avoid confusion, try not to have your Kobo eReader mounted when you try this.

Backup regularly, and when you run into database corruption issues (or a tweak run amok), you can follow the steps above, then use the following command instead for part three:

Replace "path" and "backup_disk_image.dmg" with the actual path and filename of your backup. Don't forget to change "diskX" to reflect your Kobo's drive number.

I hope this has been helpful.