我使用 iotop，这就是我得到的
Total DISK READ : 0.00 B/s | Total DISK WRITE : 15.78 M/s
Actual DISK READ: 19.08 K/s | Actual DISK WRITE: 0.00 B/s
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
16583 be/4 nobody 0.00 B/s 3.82 K/s 0.00 % 0.00 % httpd -k start
16850 be/4 mysql 0.00 B/s 7.04 M/s 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --lo~te.com.err --open-files-limit=10000 --pid-file=/var/lib/mysql/host.hostgreatsite.com.pid
16317 be/4 nobody 0.00 B/s 3.82 K/s 0.00 % 0.00 % httpd -k start
16859 be/4 mysql 0.00 B/s 3.04 M/s 0.00 % 0.00 % mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --lo~te.com.err --open-files-limit=10000 --pid-file=/var/lib/mysql/host.hostgreatsite.com.pid
1024 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % NetworkManager --no-daemon [gdbus]
1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % systemd --switched-root --system --deserialize 21
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]
5124 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/u12:0]
5 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/0:0H]
518 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % abrt-watch-log -F BUG: WARNING: at WARNING: CPU: INFO: possible recursive locking detect~ption: simd exception: iret exception: /var/log/messages -- /usr/bin/abrt-dump-oops -xtD
7 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/0]
8 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_bh]
9 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/0]
10 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/1]
11 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/2]
12 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/3]
13 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/4]
14 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuob/5]
15 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_sched]
16 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/0]
17 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/1]
18 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/2]
19 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/3]
20 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/4]
21 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcuos/5]
22 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/0]
23 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/1]
24 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/1]
25 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/1]
15898 be/4 nobody 0.00 B/s 0.00 B/s 0.00 % 0.00 % httpd -k start
27 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/1:0H]
28 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/2]
29 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/2]
30 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/2]
517 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % abrtd -d -s
32 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/2:0H]
33 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/3]
34 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/3]
35 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/3]
16420 be/4 nobody 0.00 B/s 0.00 B/s 0.00 % 0.00 % httpd -k start
37 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/3:0H]
38 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/4]
39 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/4]
40 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/4]
42 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/4:0H]
43 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/5]
44 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/5]
看起来是mysql的问题。
root@host [~]# iostat -xk 5
12/05/2016 _x86_64_ (6 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
35.35 0.05 8.48 6.11 0.17 49.84
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
xvdap1 0.26 9.95 24.20 33.63 480.30 1125.98 55.55 7.50 129.63 102.41 149.22 5.55 32.08
xvdap2 0.21 0.83 0.04 0.21 0.99 4.18 41.88 0.00 18.50 10.36 19.88 3.67 0.09
xvdap3 0.16 21.65 16.33 19.33 90.31 230.11 17.97 0.57 15.87 10.18 20.68 1.63 5.82
xvdap4 0.01 0.06 1.26 0.13 15.21 3.25 26.67 0.03 20.28 17.04 52.31 3.19 0.44
avg-cpu: %user %nice %system %iowait %steal %idle
69.67 0.00 14.01 2.17 0.27 13.88
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
xvdap1 0.00 11.40 10.40 39.80 56.80 1005.60 42.33 4.84 96.41 47.13 109.28 4.16 20.86
xvdap2 0.00 3.60 0.00 2.20 0.00 23.20 21.09 0.01 2.27 0.00 2.27 1.73 0.38
xvdap3 0.00 0.00 0.60 0.00 2.40 0.00 8.00 0.00 0.67 0.67 0.00 0.67 0.04
xvdap4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
avg-cpu: %user %nice %system %iowait %steal %idle
60.56 0.00 13.50 1.07 0.23 24.63
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
xvdap1 0.00 10.60 1.00 147.80 8.80 6284.00 84.58 10.33 69.45 6.40 69.88 0.67 9.96
xvdap2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
xvdap3 0.00 0.00 1.00 0.00 32.80 0.00 65.60 0.02 15.80 15.80 0.00 5.00 0.50
xvdap4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
它显示只有第一个驱动器 xvdap1 负载较重。
这是一个正确的结论吗？