https://bugs.kde.org/show_bug.cgi?id=458001
--- Comment #11 from flan_suse <[email protected]> --- (In reply to Méven from comment #10) > To confirm this, could you provide: > - your KDE Frameworks version > - your ZFS version, and the output of: zfs get recordsize <dataset> > - the calls Dolphin makes during a copy, from: > strace -f -e trace=copy_file_range,ioctl -p $(pidof dolphin) > (copy one large file in Dolphin while this runs, then stop it with Ctrl+C) KDE Frameworks Version: 6.31.0 ZFS Version: 2.4.2 Record size: 1M for all datasets. (From the user's perspective, it shouldn't matter if it's 32K or 16M record size.) I'll attach the log file of strace. This was over SMB, but you're saying that the fix will work for NFS too? > If the cause is confirmed, the fix is to keep the boundaries of each copied > piece aligned on a large block size. If it resolves this issue and will "just work" no matter what the record size is, that's great. I still don't understand, though. Why should Dolphin try to align anything? "cp" doesn't need anything special, as you noted it passes the whole file. What's the magic that PCManFM-Qt uses? How is it that without any tweaking or workarounds, PCManFM-Qt it is exponentially superior when copying large files over an SMB or NFS share? Not only does copying a 5 GB file happen instantly, but it takes up no additional space on the ZFS server. I can't rely on Dolphin to copy large files over SMB or NFS. I had to make a Service Menu shortcut that uses "cp" to copy the file in the same directory, which I then move to another folder, in order to take advantage of ZFS block cloning. Sometimes I find myself just using PCManFM-Qt, but then I miss out on other features of Dolphin. > The difference is the size of each copy_file_range() call. cp passes the > whole file in one call. KIO copies in > pieces: 512 KiB up to KF 6.30, and since 6.31 a size that adapts to the > speed of the copy. This is what I mean. It feels like Dolphin is trying to be too smart which ends up hurting performance and space usage efficiency. -- You are receiving this mail because: You are watching all bug changes.
