Hi, I have a problem with copying large files. For example it is almost impossible to get a 700MB movie to my flash disk. At the beginning the speed is really high (which has something to do with kernel and cache as far as I know...) but after a while the speed drops to zero and hangs. Sometimes it starts copying again and even finishes copying after about 30 minutes but sometimes not. And the most annoying is that I have to restart the whole KDE to safely unplug the device because the process is still hanging somewhere in there.

But, using pv in console works flawlessly. The speed is constant (a little bit higher at the beginning) and the whole process takes only few minutes. Therefore I am writing in KDE forum because it seems like a KIO problem to me.

Copying large files to other partitions works quite well. I have also copied a 3GB file over ftp and it was also ok.

I regularly copy large files (700MB and larger) to USB thumb drives and USB HD drives and have not experienced any problems.

I am running KDE 4.5.x on Kubuntu.

What distro and KDE version are you running and what filesystem is your flash drive formatted with?

Do you have another flash drive you can try?

Sorry, I forgot to mention it - I have OpenSuse 11.3, KDE 4.5.x, kernel 2.6.37. I tried both FAT and NTFS on my flashdisk, the result was the same. Unfortunately I don't have another flash drive to try, but this one seems to be ok on other machines.

I had the same problem with a fat32 usb mp3 player.
Recently I changed some kernel parameter to lower the need for file caching, and now I can copy files without hassle.

These are the new values I use for a better (imho) desktop performance:
vm.swappiness = 1
vm.vfs_cache_pressure=10000

reference: https://bbs.archlinux.org/viewtopic.php?id=40111

For future reference, the process responsible for copying files using KIO is usually "kio_file".

bcooksley wrote:For future reference, the process responsible for copying files using KIO is usually "kio_file".

Well I tried to determine the problematic process using lsof and fuser but they showed much more processes - it actually looked like the whole KDE (therefore I decided to restart KDE in order to unmount flash drive properly). But I try to kill kio_file next time.

frasty wrote:I had the same problem with a fat32 usb mp3 player.
Recently I changed some kernel parameter to lower the need for file caching, and now I can copy files without hassle.

These are the new values I use for a better (imho) desktop performance:
vm.swappiness = 1
vm.vfs_cache_pressure=10000

reference: https://bbs.archlinux.org/viewtopic.php?id=40111

Thanks for the tip, I will try it.