in linux, system is slowed very much and CPU 100% when I copy from (non-system-based) usb HDD to another usbHDD. Why?

My CPU is 100%. I was told that CPU can be 100% without system be slowed down.System Monitor tells: MEM 5GB/15.6Gb Swap 3GB/16GB. System-monitor tells that apps use max 8%. Where is the other 92% that refers to 100% in cpu tab?

enter image description here enter image description here

I have active qbittorent that is using a lot of I/O processes in non-system disks. However, this (alone) did not created problems in system slowness.

When moved files from an (old usb HDD - 2gb passport) to a higher-speed passport (usb hdd 5GB) system slowed down to point of almost halting. This means that it may took 1-3 minutes until a letter from keyboard is written on the text editor. Move was performed through dolphin.

     _,met$$$$$gg.           elias@eliasc
      ,g$$$$$$$$$$$$$$$P.        OS: Debian 11 bullseye
    ,g$$P""       """Y$$.".      Kernel: x86_64 Linux 5.11.0-18-generic
   ,$$P'              `$$$.      Uptime: 20d 20h 40m
  ',$$P       ,ggs.     `$$b:    Packages: 6436
  `d$$'     ,$P"'   .    $$$     Shell: bash
   $$P      d$'     ,    $$P     Resolution: 1920x1080
   $$:      $$.   -    ,d$$'     DE: KDE 5.80.0 / Plasma 5.21.4
   $$\;      Y$b._   _,d$P'      WM: KWin
   Y$$.    `.`"Y$$$$P"'          GTK Theme: Breeze [GTK2], Adwaita [GTK3]
   `$$b      "-.__               Icon Theme: breeze
    `Y$$                         Disk: 20T / 26T (83%)
     `Y$$.                       CPU: Intel Core i5-4570S @ 4x 3.6GHz [45.0°C]
       `$$b.                     GPU: NV138
         `Y$$b.                  RAM: 5975MiB / 15961MiB

So my questions are:

  1. How can i find what is slowing down my system?
  2. Why i/o processes of moving files from non-system usb hdd slow down my system?
  3. Why system-monitor refers in app tab 8-10% CPU load while in CPU tab tells 100% load? where is the other 92%?
  4. What I can do in order system to not slow down during moving files?
  5. Weird behaviour - If i leave the system lets say for 1 hour, in order to de-halt system, i must move mouse or stroke keyboard keys in order "to claim" resources" back. This may take 10 minutes or more until system is "user-usable" again!
  6. (UPDATE) using iotop i found that is creatng a slave folder at system hdd. Why? is that taking resources? (see pic).

Dont know why moving files is making that system so slow down, and i dont know any app to measure that somehow or what countermeasures i can take.

iotop stats for linux system disk (%wrqm dont know why is so high) (ext4 500 GB — 70 GB free).

Device            r/s     rMB/s   rrqm/s  %rrqm r_await rareq-sz     w/s     wMB/s   wrqm/s  %wrqm w_await wareq-sz     d/s     dMB/s   drqm/s  %drqm d_await dareq-sz     f/s f_await  aqu-sz  %util
sda              5.33      0.22     3.06  36.52   14.14    42.85    9.97      0.41    25.28  71.71   17.21    42.41    0.00      0.00     0.00   0.00    0.00     0.00    2.92   35.51    0.35  18.04
qu-sz  %util

active io processes

  • What usb (2?3?) what filesystem involved (ext? fat?) copied via dolphin ? => which version of kio-slaves ? (BTW your system is actively swapping)
    – MC68020
    Nov 7, 2022 at 18:43
  • all ext. Yes the move of files were done through dolphin. kio-slaves version? how i can find that? I couldnt find any related info on web about kio-slaves version in terminal. KDE Frameworks: 5.80.0 Qt Version: 5.15.2 Kernel Version: 5.11.0-18-generic OS Type: 64-bit Nov 13, 2022 at 11:38
  • kio is responsible for copying files via dolphin. It has a long history of clumsy behavior. It belongs to the kde-frameworks and is somehow improved with each new release… BTW… AFAIK… 5. 96 is current, your 5.80 seems way behind. Please A/ Confirm you observe the same when copying with basic shell's cp B/ When copying via dolphin you should get some status notifier displaying some progress bar. Is the progress bar rapidly reaching 100% then stays there for ages ? In which part of the job your cpu is the most sollicitated (when progressing / after having reached 100%) ?
    – MC68020
    Nov 13, 2022 at 17:51
  • 1
    I did it today. I mass copy files from usb hdd to another usb hdd using bash (mv -fv * destination). No, my system was not slowed down as before. It was very operative. Nov 16, 2022 at 22:15
  • 1
    Nice ! Now then you can rightly accuse the kio-slaves. (Not personally surprised considering the version of the frameworks you are running).
    – MC68020
    Nov 16, 2022 at 22:50


You must log in to answer this question.

Browse other questions tagged .