Bug 489762

Summary:	Thumbnails generated on a ZFS filesystem are not saved to the cache
Product:	[Applications] dolphin	Reporter:	ipha <ipha00>
Component:	general	Assignee:	Dolphin Bug Assignee <dolphin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	bugs.kde.org.shine600, kfm-devel, saucesfm
Priority:	NOR
Version First Reported In:	24.05.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=488283
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description ipha 2024-07-05 01:23:58 UTC

SUMMARY
When browsing a folder with media on a ZFS filesystem, thumbnails are generated correctly but not saved to the cache. Reopening the same folder causes the thumbnails to be re-generated each time.

STEPS TO REPRODUCE
1.  Clear ~/.cache/thumbnails
2.  Browse a folder on a ZFS mount with pictures, let thumbnails generate
3.  Check ~/.cache/thumbnails, it's still empty

OBSERVED RESULT
Thumbnails are not saved to the cache

EXPECTED RESULT
Thumbnails should be saved to the cache


SOFTWARE/OS VERSIONS
KDE Plasma Version: 6.1.2
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.2

Comment 1 Petr N. 2024-12-19 06:08:37 UTC

I am also using ZFS (on external, not system drive) and the thumbnail generation works (is saved to the cache folder).
Add new image to a ZFS filesystem, run "find ~/.cache/thumbnails/ -mtime -2" and open last thumbnail in a image viewer to see if it is the expected one.

$ inxi -S
Debian 12 (stable), 6.1.0-27-amd64, KDE 5.27.5

$ dolphin --version
dolphin 22.12.3

$ zfs --version
zfs-2.1.11-1+deb12u1
zfs-kmod-2.1.11-1+deb12u1

Comment 2 saucesfm 2024-12-30 01:08:37 UTC

I am seeing the same issue on my desktop PC, but not on my Mini PC. Both are running Arch Linux with the same package versions. I notice the thumbnailing is working on the root partition which is ZFS, but not on any any other ZFS pools mounted on /run/media/username.

The one difference between them is that my desktop's root partition is on an unencrypted ZFS drive, but the mini pc's root partition is on an encrypted BTRFS drive, and I am wondering if its related to this somehow. https://bugs.kde.org/show_bug.cgi?id=443806 because thumbnails are being generated, but not cached.

KDE Plasma 6.2.4
KDE Frameworks 6.9.0
Qt Version: 6.8.1