On Sat, 4 Oct 2014 16:55:32 +0200 Florian Koch florian.koch1981@gmail.com wrote:

Now if i copy big files e.g Centos7 ISO, KDE becomes unresponsive for some time (from seconds to minutes ).

As a test, I copied a factory DVD iso to "/tmp". That's a copy between two different partitions. I did not have the problem that you describe. Response was slighly slower than usual, but still within reason.

I have an older computer that used to be my main desktop system. On that computer, I would see the kind of behavior that you describe. I typically saw it when copying an iso to a USB, as in

# dd_rescue /path/to/file.iso /dev/sdX

In that case, I could move the mouse but the pointer would not move until perhaps a minute later. Usually, I would start that copy, then take a coffee break. This was happening back at opensuse 11.4, 12.1, 12.2. I do not notice this on my current desktop.

I think it's partly a hardware issue. The copy is hogging the bus or the interrupt handler or something.

The simplest solution seems to be to take a coffee break (or some other break) during the copy.