OS is terribly slow when copy or tar/untar files

Is possible to setup CPU load or RAM for better multitasking? Because when I for example copy files or tar/untar some bigger file, OS is terribly slow due this operation.

Thanks.

OS Ubuntu 18.04.

HW CPU i7, 8GB RAM, SSD.

Update

When tar zxvf SOME_BIG_FILE.tar.gz (file about 3GB), due this process is not possible to work, switching between windows with ALT+TAB takes 2 seconds, keyboard and mouse get stucked in 5 seconds interval.

CPU is not so high (sometimes some process takes me more and all is ok).

Tasks: 303 total, 1 running, 251 sleeping, 0 stopped, 1 zombie
%Cpu(s): 20,2 us, 5,8 sy, 0,0 ni, 64,8 id, 7,2 wa, 0,0 hi, 1,9 si, 0,0 st
KiB Mem : 8031476 total, 174684 free, 6087096 used, 1769696 buff/cache
KiB Swap: 3906556 total, 2917856 free, 988700 used. 1113008 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6916 hosek 20 0 4912 840 776 D 82,4 0,0 0:17.75 gzip 6915 hosek 20 0 42152 3536 3256 S 13,6 0,0 0:03.24 tar 148 root 20 0 0 0 0 S 4,7 0,0 7:44.14 kswapd0 6917 root 20 0 0 0 0 D 2,3 0,0 0:00.12 kworker/u8:3+fl 1964 root 0 -20 0 0 0 I 1,3 0,0 0:08.80 kworker/1:1H-kb 

And memory seems OK too.

 total used free shared buff/cache available
Mem: 8031476 6026968 169716 540912 1834792 1103756
Swap: 3906556 927004 2979552

I suppose this is some disk process related? Or how can I find out brownie?

1 Answer

It seems you have disk IO priority issue.

You could specify lowest priority for processes which perform disk operations.

ionice -c 3 tar zxvf SOME_BIG_FILE.tar.gz

From man ionice:

ionice [-c class] [-n level] [-t] command [argument...]
OPTIONS -c, --class class Specify the name or number of the scheduling class to use; 0 for none, 1 for realtime, 2 for best-effort, 3 for idle.

Another possible solution is to use lowlatency kernel, which will make more resource intensive operations slower, but will improve responsiveness. Reference.