Needless caching of jpeg files - how to eliminate?

There is some caching of thumbnails or files’ information happening when marking many photo files to view. This seems needless and was not present in opensuse 13.2.

Here are the details. In Dolphin, I select many hundred jpeg files to be viewed. The files’ background changes color. Then do right click -> Open With, and select a viewer.

Instead of the viewer starting, a disk activity starts, at a rate of 100 disk access requests per second, to /home partition. Then, after a few seconds, the viewer starts.

I don’t want this to happen, since it delays my viewing of the first photo, and, evidently, puts a high load on the HD which makes quite loud sound of heads moving under that load.

Can this behavior be suppressed? I don’t want any thumbnailing, icon saving, caching, pre-loading, indexing or similar.

I have folders with thousands of photos. I simply click the first one, Gwenview opens and I can navigate through the folder items. Why select them first?

Because from a long list, I would like to select certain groups, say, shot during a year:


First, 13.2 had KDE4, you now have the KDE Plasma 5 desktop, which has it’s config files and probably more in different places. I have my doubts about KDE4 on 13.2 not caching such files, rather think Plasma 5’s activity is related to building a new cache. But, that’s just some idea. I don’t see any excessive caching here on TW, nor on Leap 42.2

In my computer, after calling Gwenview, it takes 30 seconds for 500 images to be thumbnailed or processed in some other way until Gwenview’s view screen comes up.

Next time I start Gwenview, the same happens.

During thumbnailing, the hard drive is emitting sound similar to the one from a big broken fan. It is evidently a very unpleasant load for the hard drive.

I would like to avoid thumbnailing or caching. Cannot find any place in KDE or viewers to disable.

Check your drive for weak or bad sectors

Maybe in Dolphin?Settings -> Configure Dolphin -> General -> Previews uncheck JPEG ?

The hard drive is old but good. I use it every day for /home.
smartctl shows no errors in

5 Reallocated_Sector_Ct
7 Seek_Error_Rate
10 Spin_Retry_Count
197 Current_Pending_Sector
198 Offline_Uncorrectable

There is one error in

199 UDMA_CRC_Error_Count

but it is there since long time. I don’t want to run badblocks in non-destructive mode, though.

I have transferred the folder with photos to another hard drive in the same computer; observed the same.

Then I transferred the files onto an SSD in the same computer; observed the same (loaded) behavior of /home hard drive. This tells me that the thumbnailing is happening in /home.

The preview of jpeg files in Dolphin was disallowed:

Settings -> Configure Dolphin -> General -> Previews uncheck JPEG

Check the gwenview setting

I disabled as much as possible in terms of caching and thumbnailing in Gwenview. It has no effect. Other viewers behave similarly, load the disk and take same amount of time.

Interestingly, the caching/thumbnailing behavior is different when the viewer is started from command line:

gwenview pattern*.jpg

The viewer’s screen is immediately available. The thumbnailing/caching behavior depends on viewer, but the first picture is available immediately.

Evidently, this is an unwanted service from KDE. Maybe they were thinking, that one will never view hundreds of marked photos. (If thousands of photos are viewed, this needless preparation is going to take 5 minutes in my computer!) I tried to find in which folder does the caching or thumbnailing occur; couldn’t. Maybe photos are only read, thumbnails created and stored in RAM.

Well, the KDEians could at least allow starting of the viewer screen before thumbnailing is finished. What is required for that?

When you think it is a KDE design flaw, you could ask on the KDE forums, or even (maybe after asking on the forums first) filing a bug report with KDE.

KDE forums:
KDE bugs:

Try setting all permissions (owner/group/others) on “~/.cache/thumbnails/” to “forbidden” :\

Bug report to KDE is submitted.

I don’t have
folder. There are some *.kcache files in ~/.cache/ folder.

OK… maybe “~/.thumbnails” then.

Although I see from a reply to your bug report ( 372999 – Compress and Extract plugins freezing application for long time if many files selected ) it appears a known problem.

There is nothing relevant in ~/.thumbnails

I couldn’t find a definite place where the thumbnails or cached images are saved. A candidate is file


but it seems to have 11 MB size always.

Thumbnails generated by Dolphin/Gwenview are stored at “~/.cache/thumbnails/” when using plasma5 (“~/.thumbnails” with KDE4).

A candidate is file


but it seems to have 11 MB size always.

That’s the cache for the icon theme (Breeze or whatever) that you’re using.

But, as I wrote in post #14 your problem seems to be a known issue which is in the process of being fixed.