CentOS 6

A couple of days back an update to Firefox caused the program to start creating and storing thumbnails withing the Firefox profile hierarchy. I was able to fix this by adding to about:config the following key:While I was at it I went looking for other unwanted thumbnails. And I found them in /home/ken/.thumbnails :-(

I reviewed my build notes and found this: I checked and verified that the setting was still set. I noted that a number of thumbnailers, particularly related to evince, had individual settings and were enabled. I disabled them as well. But still the system is generating thumbnails. For example if I right click on the Desktop and select Change Desktop Background I see a bunch of files appearing in .thumbnails. So it appears that some thumbnailer is still functioning.

How do I disable all thumbailers, everywhere, always and permanently?

TIA,

Ken

I gave up on that! Instead I wrote a script to be run at start-up to delete all the thumbnails and the flash cookies too.

~/.thumbnails/large
~/.thumbnails/normal

are part of the desktop operations
if a pdf is viewed in okluar the desktop will make a thumbnail


for kde and gmone
it is under "folder properties"
set preview to 0 kb

Thanks DavidMcCann,

I have had commands in my nightly housekeeping/backup script to delete thumbnails, cache and various other crap. I have been running, and adding to the script for YEARS. My concern here is not to simply get rid of the thumbnail files for PRIVACY and/or other reasons. Rather it is to turn off the thumnailer programs for SECURITY reasons. I saw a fantastic video a couple of years ago of a computer conference where the presenter locked the screen on a Linux box and inserted a flash drive with a bunch of graphics files, one of which contained some thumbnailer exploit code. In less than a minute the compromised thumbnailer executed a script which killed the screen saver and unlocked the machine! I immediately disabled (or at least I thought I disabled) thumbnailers on all my Linux machines.

Thanks John VV,

I am not using okular on this machine. It looks like I have killed the thumbails on evince for the time being at least. In gnome file browser (Nautilus) I have everything set to list view (not icons) and all Previews set to Never. I have stopped Firefox from creating thumbnails but Appearance Preferences still creates them.

Getting dangerous now... I just found a setting in gconf-editor /desktop/gnome/thumbnail_cache. I will set the max age and max size values to 0 and see if the machine tilts.

Well, it did not tilt, invoking Appearance Preferences created the thumbnails but they went away after a minute or so(?) Perhaps I will just do a chmod -x on .thumbnails and forget about it.

Ken

Would this work?
Haven't tried it myself, and I'd like to know what BAD things can happen in a thumbnailless world?

[Edit]@taylorkh Started my post before your last appeared. Thought you were only interested in getting rid of cruft.

[QUOTE=impert;4898865]Would this work?
In case that throws errors (because noone can create files in /dev/null, only dump stream data to it), you could also use a tmpfs (ramdisk) directory. If you have mounted e.g. /tmp as tmpfs you can do (e.g. during boot or desktop startup):

mkdir -p /tmp/ken/.thumbnails
chown ken /tmp/ken/.thumbnails

If not already done, do this once:
rm -rf ~/.thumbnails
ln -s /tmp/ken/.thumbnails ~/.thumbnails

That's what i do. Just too many applications write thumbnails without my explicit consent, so i let them write to a ramdisk as i got plenty of RAM. The thumbs will stay available until i shutdown/reboot which isn't so bad.

This thumbnail generation is really annoying. It should be disabled by default in all applications as a matter of software standard behavior. What if i don't wish to leave any traces of whatever images i was ever viewing? Also a privacy issue.. same with histories of any kind. Programs just generate them. Ppl who write such software apparently live in a world where noone would ever spy on you.. e.g. by confiscating your computer..