*** If you're not sure this is actually a bug, instead post about it at https://discuss.kde.org If you're reporting a crash, attach a backtrace with debug symbols; see https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports Please remove this comment after reading and before submitting - thanks! *** SUMMARY Large file copies corrupt the target copy. STEPS TO REPRODUCE 1. Copy a large (in my case a 10G file) to a fstab mounted CIFS share 2. Check integrity of copied file. A CRC comparision or archive with a check will show a failed copy. 3. Note that this does not happen with Krusader, PCManFM, or even a 'cp' between the two paths. OBSERVED RESULT EXPECTED RESULT SOFTWARE/OS VERSIONS Windows: macOS: (available in the Info Center app, or by running `kinfo` in a terminal window) Linux/KDE Plasma: KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
Tested with NFS and no corruption. Dolphin through a KIO slave is ok too. I've noticed that the copy through a CIFS mount via fstab is buffering almost the whole copy into RAM then pushing it through. Perhaps some kind of background memory issue with that route. Checked RAM sticks and tested. Swapped RAM too. It's only that copy path. I can use KIO for a bit until things settle with other parts and discuss over at the discuss area :-)
I can second this, and here is another report: https://superuser.com/questions/1814677/files-are-corrupt-after-copying-streaming-them-from-samba-fileshare Copying using cp, rsync or any other tool on a SMB mount works. Copying via Dolphin will corrupt the file. Workaround: add "cache=none" to the SMB server's mount options so that the file copy process is not cached. Then, also Dolphin can copy the file without errors. And as an additional bonus the copying speed doesn't oscillate so much any more. This is not a fix however. And I think this is quite a serious issue. How can we help finding the root cause of this?
Created attachment 180928 [details] attachment-1128998-0.html I can confirm the addition of cache=none stops the big cache load/flush cycle and indeed keeps things steady with the copy. The target copy did verify correctly. This was to my file server with SMB multichannel disabled. Update: server set to SMB multichannel also is working, and same speed as expected. I tried this before about two months ago and cache=none had no effect, so something changed in the meantime :-). I agree that this seems to be a workaround however. I'm still not 100% sold that it is rock solid and I have been using NFS. In the meantime, I will go with this being a KDE issue. How can I help to further find the cause of this? TY! Kev. On May 3, 2025 1:35 PM, Jens wrote: > https://bugs.kde.org/show_bug.cgi?id=501118 > > Jens<jens-bugs.kde.org@spamfreemail.de> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |jens-bugs.kde.org@spamfreem > | |ail.de > > --- Comment #2 from Jens<jens-bugs.kde.org@spamfreemail.de> --- > I can second this, and here is another report: > https://superuser.com/questions/1814677/files-are-corrupt-after-copying-streaming-them-from-samba-fileshare > > Copying using cp, rsync or any other tool on a SMB mount works. Copying via > Dolphin will corrupt the file. > > Workaround: add "cache=none" to the SMB server's mount options so that the file > copy process is not cached. > Then, also Dolphin can copy the file without errors. And as an additional bonus > the copying speed doesn't oscillate so much any more. > > This is not a fix however. And I think this is quite a serious issue. > How can we help finding the root cause of this? >
Created attachment 181354 [details] attachment-2592318-0.html I can confirm the addition of cache=none stops the big cache load/flush cycle and indeed keeps things steady with the copy. The target copy did verify correctly. This was to my file server with SMB multichannel disabled. On May 3, 2025 1:35 PM, Jens wrote: https://bugs.kde.org/show_bug.cgi?id=501118 Jens <jens-bugs.kde.org@spamfreemail.de> <jens-bugs.kde.org@spamfreemail.de> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jens-bugs.kde.org@spamfreem | |ail.de --- Comment #2 from Jens <jens-bugs.kde.org@spamfreemail.de> <jens-bugs.kde.org@spamfreemail.de> --- I can second this, and here is another report: https://superuser.com/questions/1814677/files-are-corrupt-after-copying-streaming-them-from-samba-fileshare Copying using cp, rsync or any other tool on a SMB mount works. Copying via Dolphin will corrupt the file. Workaround: add "cache=none" to the SMB server's mount options so that the file copy process is not cached. Then, also Dolphin can copy the file without errors. And as an additional bonus the copying speed doesn't oscillate so much any more. This is not a fix however. And I think this is quite a serious issue. How can we help finding the root cause of this?