DirectAdmin 向我发送了以下top输出：
This is an automated message notifying you that the 5 minute load average on your system is 179.99.
This has exceeded the 10 threshold.
One Minute - 171.19
Five Minutes - 179.99
Fifteen Minutes - 170.21
top - 10:30:55 up 11 days, 23:48, 0 users, load average: 138.58, 160.32, 164.04
Tasks: 605 total, 2 running, 603 sleeping, 0 stopped, 0 zombie
Cpu(s): 2.9%us, 0.8%sy, 0.0%ni, 88.5%id, 7.6%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1920560k total, 1866292k used, 54268k free, 2040k buffers
Swap: 10485752k total, 4295252k used, 6190500k free, 35208k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23 root 20 0 0 0 0 S 0.7 0.0 4:33.08 [kblockd/1]
22 root 20 0 0 0 0 S 0.5 0.0 3:02.55 [kblockd/0]
13874 apache 20 0 733m 8704 4032 D 0.2 0.5 0:03.90 /usr/sbin/httpd -k start -DSSL
1431 mysql 20 0 1654m 40m 1932 S 0.2 2.2 96:29.55 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/server.com.err --pid-file=/var/lib/mysql/server.com.pid --socket=/var/lib/mysql/mysql.sock --port=3306
1520 mail 20 0 59344 596 500 S 0.2 0.0 0:19.71 /usr/sbin/exim -bd -q15m -oP /var/run/exim.pid
14163 apache 20 0 735m 10m 5300 D 0.1 0.5 0:03.51 /usr/sbin/httpd -k start -DSSL
13922 apache 20 0 737m 9040 4960 S 0.1 0.5 0:04.09 /usr/sbin/httpd -k start -DSSL
14181 apache 20 0 739m 17m 3284 D 0.1 1.0 0:04.36 /usr/sbin/httpd -k start -DSSL
28173 root 20 0 15420 1584 852 R 0.1 0.1 0:00.09 /usr/bin/top -c -b -n 1
14157 apache 20 0 739m 7696 3252 S 0.1 0.4 0:03.15 /usr/sbin/httpd -k start -DSSL
14217 apache 20 0 740m 14m 3860 D 0.1 0.8 0:03.37 /usr/sbin/httpd -k start -DSSL
14615 apache 20 0 734m 7984 3116 D 0.1 0.4 0:02.34 /usr/sbin/httpd -k start -DSSL
14644 apache 20 0 734m 9660 4080 D 0.1 0.5 0:03.36 /usr/sbin/httpd -k start -DSSL
15159 apache 20 0 727m 13m 4928 S 0.1 0.7 0:01.47 /usr/sbin/httpd -k start -DSSL
15202 apache 20 0 727m 9396 4812 D 0.1 0.5 0:01.73 /usr/sbin/httpd -k start -DSSL
15362 apache 20 0 734m 7484 5032 D 0.1 0.4 0:03.17 /usr/sbin/httpd -k start -DSSL
15498 apache 20 0 723m 8924 4996 D 0.1 0.5 0:02.36 /usr/sbin/httpd -k start -DSSL
15577 apache 20 0 723m 9892 5276 D 0.1 0.5 0:02.42 /usr/sbin/httpd -k start -DSSL
19951 apache 20 0 723m 10m 5344 D 0.1 0.6 0:01.47 /usr/sbin/httpd -k start -DSSL
28167 root 20 0 15420 1584 852 R 0.1 0.1 0:00.10 /usr/bin/top -c -b -n 1
4 root 20 0 0 0 0 S 0.1 0.0 2:52.17 [ksoftirqd/0]
11 root 20 0 0 0 0 S 0.1 0.0 11:36.80 [events/0]
39 root 20 0 0 0 0 D 0.1 0.0 1:34.68 [kswapd0]
我无法理解为什么平均负载如此高，平均负载通常是load average: 0.48, 0.23, 0.14。那么，这里究竟发生了什么？我没有看到任何进程使用任何内存，也没有任何进程使用高 CPU %，那么到底发生了什么？
答案1
负载值非常高的原因是您有许多 Apache 进程（可能永久）被 I/O 阻塞。它们不消耗 CPU，但会增加负载。