Unknown disk activity in linux?

Question

linux

Constantly someone completely eats one core out of 7 on iowait and this consistently generates +1 to load average, the core has been occupied by iowait for several months.

top - 11:29:26 up 173 days,  8:52,  1 user,  load average: 1.21, 1.27, 1.30
Tasks: 240 total,   1 running, 239 sleeping,   0 stopped,   0 zombie
Cpu0  :  3.0%us,  0.7%sy,  0.0%ni,  0.0%id, 95.6%wa,  0.0%hi,  0.3%si,  0.3%st
Cpu1  :  0.3%us,  0.7%sy,  0.0%ni, 99.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu2  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu3  :  0.0%us,  0.3%sy,  0.0%ni, 99.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu4  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu5  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu6  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu7  :  0.3%us,  0.3%sy,  0.0%ni, 99.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st

iotop is almost always empty like this

Total DISK READ:       0.00 B/s | Total DISK WRITE:       0.00 B/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND
16896 be/4 deploy      0.00 B/s    0.00 B/s  0.00 %  0.00 % searchd --pidfile --config 
    1 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % init
    2 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kthreadd]
    3 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [ksoftirqd/0]
    5 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kworker/u:0]
    6 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/0]
    7 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [watchdog/0]
    8 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/1]
   10 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [ksoftirqd/1]
   11 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [watchdog/1]

Only the rail application is running on the server and there is nothing to create a load on the disk.

Answer 1

Maybe it's some kind of dead process. Sometimes it happens that the process ended incorrectly, and some of its remnants in memory continue to work with the disk. As a result, do not restart the computer yet. so it will rustle on the disk.

Answer 2

ps ax | grep D show

Answer 3

Try running "iotop -a -o" for a while (as root).