Dolphin 17.03.70 Plasma 5.8.90 Frameworks 5.29.0 Qt 5.7.0 The problem is best reproduced in dolphin filemanager. A remote share (owncloud) mounted with davfs2 seems to be treated as local filesystem. Therfore the setting "don't create thumbnails for remote files bigger than.." is not honored and previews of files and folders are being created. Deactivating folder previews works as quickfix for the critical situations but files bigger than 10 MB still completely stall dolphin. The davfs2 option "gui_optimize" also improves the situation a little bit but the problem remains. Also giving the thumbnailcreator more power did not really help. /usr/share/kservices5/thumbnail.protocol maxInstances=4 Entering any folder that contains even very small videos almost kills dolphin. It takes forever until you gain control again.
https://invent.kde.org/frameworks/kio/-/merge_requests/702
Git commit afb37351506046272adcfd05213a9c5fa697e9fc by Ahmad Samir, on behalf of Bharadwaj Raju. Committed on 02/02/2022 at 09:54. Pushed by ahmadsamir into branch 'master'. Consider slow files as remote files in previewjob Consider files which are slow according to `KFileItem::isSlow()` as remote files. This makes browsing FUSE remote mounts (like with rclone) much smoother. Such mounts are still `isLocalFile()`, even though they represent a remote resource. Related: bug 349161 M +1 -1 src/widgets/previewjob.cpp https://invent.kde.org/frameworks/kio/commit/afb37351506046272adcfd05213a9c5fa697e9fc
The commit from comment#2 was reverted https://invent.kde.org/frameworks/kio/-/commit/be7d351a8ac4cccc5e66b1d278326e6f26ead1c0
Had to be reverted unfortunately as it caused regression https://invent.kde.org/frameworks/kio/-/commit/be7d351a8ac4cccc5e66b1d278326e6f26ead1c0 We will revisit this, once we have improved our ntfs/fuse detection.
Can I please add to this - the issue is actually worse than just slow previews. The davfs2 cache is exhausted almost immediately for any moderately sized or greater davfs2 share (when mounted via autofs or mount.davfs2), causing Dolphin (etc) to crash and the network share to hang, and transfer speed is irrelevant in this case.