Extra .sdr files

[Georgie W]

Since about March 2018, I'm getting extra .sdr folders created in the Documents directory on my Kindle PW3 for every book I open and read.

So I have the original author folder (Christie), and inside that, an .sdr folder for "Murder on the Orient Express". But if I read the book, I get a second MotOE .sdr file created in the Documents directory itself. I can delete it from Windows Explorer, but it's a minor irritation. Why are these extra directories being created, and how do I stop them? Any help gratefully received!

I have a JB PW3, on 5.9.4. which hasn't gone on line for the last month (and I'm trying to keep it that way, because it's such a pain getting KUAL to run again after each FW update). I load all books on to the Kindle via Calibre Send to Device.
Thanks.

[hius07]

You cannot stop creating them.
You can clean up the orphan .sdr with the KUAL extention or with the desktop app.

[baalajimaestro]

They are intended to be created. Only thing is you can remove only orphaned sdr. Not the one that has a book on the drive. It'll get regenerated anyway.

[PoP]

Originally Posted by hius07

...
You can clean up the orphan .sdr with the KUAL extention...

In addition, I added

find /mnt/us/documents -depth -type d -exec rmdir {} \;

at the end of the remove.sh script to also prune empty directories.

[Georgie W]

Thanks to all for comments and suggestions - I'll try the KUAL extension. Still puzzled as to why the files should be created in the first place - maybe came in with 5.9.2.1, but it's messy.

[NiLuJe]

They're mostly cache/index/settings so-called "sidecar" files needed by various parts of the reader for various things (mostly, performance, and keeping track of stuff).

New features and/or code changes mean new/different files.

[mergen3107]

Do you guys know what indices are used in these folders?
Besides .apnx files, there are sometimes .azw3f and .awz3r files (it is when you create bookmarks, highlights and notes).
So if you tranfer a book (with highlights and stuff), let's say, in azw3 + its respective .sdr folder, then you can read these highlights and stuff. However, new kindle will create its own azw3f and azw3r files, but with own indices.

For example, take this book and put it on your Kindle.
If you do everything right, you'll see my bookmark, highlight and a note on the first page.

So I want to write a script to "adapt" these highlights for easy sharing.
I don't know how to generate these indices.

[Two Rocks]

I believe the reason there are two *.sdr folders for every book is because one is created by Calibre when the book is sideloaded onto the Kindle, and the second is created by the Kindle when the book is opened. Prior to sometime late '17 / early '18, Kindle would use the *.sdr folder created by Calibre, even though it was buried in the folder hierarchy. A change in the Kindle OS has blinded Kindle to the existence of the Calibre-created *.sdr folder, so it creates another when the book is opened. This makes the Calibre-created *.sdr folder superfluous, and it can be deleted at any time. Not sure why Calibre continues to create a folder that will not be used?

The above statements are my belief, based on experience and small indications such as file creation dates, etc. They are not fact, based on actual knowledge of Calibre and Kindle OS. Perhaps someone with actual knowledge can chime in and let us know the truth of the matter.