Estou tentando resolver tempos de espera de E / S extremamente altos. Você pode me dizer o que esta saída iotop deve me fazer?

Question

Total DISK READ :     526.37 K/s | Total DISK WRITE :     111.99 K/s
Actual DISK READ:     526.37 K/s | Actual DISK WRITE:      89.59 K/s
PID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND                                                                       

209 be/3 root          0.00 B      3.40 M  0.00 % 16.03 % [jbd2/xvda1-8]
  6 be/4 root          0.00 B      0.00 B  0.00 % 13.68 %[kworker/u30:0]
2918 be/4 www-data    171.00 K     20.00 K  0.00 %  5.77 % apache2 -k start
2386 be/4 www-data    206.00 K     16.00 K  0.00 %  5.11 % apache2 -k start
2263 be/4 www-data    300.00 K     24.00 K  0.00 %  3.93 % apache2 -k start
2359 be/4 www-data    336.00 K     16.00 K  0.00 %  3.87 % apache2 -k start
2658 be/4 www-data    852.00 K     32.00 K  0.00 %  3.64 % apache2 -k start
2749 be/4 www-data     44.00 K     16.00 K  0.00 %  3.37 % apache2 -k start
2674 be/4 www-data    333.00 K     32.00 K  0.00 %  3.03 % apache2 -k start
2748 be/4 www-data    234.00 K     20.00 K  0.00 %  1.47 % apache2 -k start
2611 be/4 www-data     49.00 K     24.00 K  0.00 %  1.37 % apache2 -k 

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          6.30    0.00    2.23   47.19    3.00   41.27

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
xvda             12.56    34.75   60.24   41.63   420.43   319.11    14.52    25.88  254.04   87.30  495.31   4.78  48.74
xvdb              0.00     0.00    0.69    0.00     2.61     0.00     7.56     0.00    0.32    0.32    0.00   0.32   0.02
xvdf             11.73     2.42  422.57    2.03   506.97    25.17     2.51     0.76    1.79    1.76    7.82   0.14   5.76