TODO：如何模拟cpu打满，磁盘打满，网卡打满

背景：

测试活动中，需要构造cpu打满、磁盘打满、网卡打满的场景

场景1：cpu打满

环境信息：

虚拟机，物理核数16个，每个物理核的虚拟核数1个，虚拟核数16个：

[root@vm10-0-0-8 test_data]# cat /proc/cpuinfo| grep "physical id"| sort| uniq| wc -l
16
[root@vm10-0-0-8 test_data]# cat /proc/cpuinfo| grep "cpu cores"| uniq
cpu cores       : 1
[root@vm10-0-0-8 test_data]# cat /proc/cpuinfo| grep "processor"| wc -l
16

top命令查看到当前cpu 占用率：

[root@vm10-0-0-8 test_data]# top
top - 21:20:02 up 16 days,  6:07,  6 users,  load average: 10.29, 8.05, 3.80
Tasks: 198 total,   1 running, 197 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us,  0.1 sy,  0.0 ni, 99.9 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 32778624 total, 18760920 free,   701276 used, 13316428 buff/cache
KiB Swap:        0 total,        0 free,        0 used. 31481428 avail Mem

%Cpu(s):

0.0 us,用户占用率（没有nice调度过）

0.1 sy,系统占用率

0.0 ni,用户空间通过nice调度过的程序cpu占用率

99.9 id,idle，空闲率

0.0 wa, 0.0 hi, 0.0 si, 0.0 st

构造cpu打满的场景：

[root@vm10-0-0-8 test_data]# cat while_1.sh 
#!/bin/bash

function while_1()
{

    while ((1)); 
    do
        i=2; 
    done
}

while_1 &

执行while_1.sh后，发现cpu中1个core被打满了：

[root@vm10-0-0-8 test_data]# sh while_1.sh
[root@vm10-0-0-8 test_data]#
[root@vm10-0-0-8 test_data]# ps -ef |grep while_1.sh
root     21553     1 99 21:29 pts/4    00:00:03 sh while_1.sh

[root@vm10-0-0-8 test_data]# top
top - 21:29:54 up 16 days,  6:17,  6 users,  load average: 1.17, 4.11, 3.58
Tasks: 196 total,   2 running, 194 sleeping,   0 stopped,   0 zombie
%Cpu(s):  4.5 us,  1.7 sy,  0.0 ni, 93.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 32778624 total, 18763900 free,   698328 used, 13316396 buff/cache
KiB Swap:        0 total,        0 free,        0 used. 31484616 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
21553 root      20   0  113176    392    200 R 100.0  0.0   0:20.97 sh

将16个core都打满：

[root@vm10-0-0-8 test_data]# cat run_while.sh
#!/bin/bash

function while_1()
{
    while ((1));
    do
        i=2;
    done
}

function run_while()
{
    for ((i=0; i<$1; i++));
    do
        while_1 &
    done
}

run_while $1

[root@vm10-0-0-8 test_data]# sh run_while.sh 16    （16是core的数，可自定义）
[root@vm10-0-0-8 test_data]# ps -ef |grep while
root     21751     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21752     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21753     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21754     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21755     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21756     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21757     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21758     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21759     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21760     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21761     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21762     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21763     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21764     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21765     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16
root     21766     1 99 21:31 pts/4    00:00:55 sh run_while.sh 16

查看cpu占用清空，idle为零了：

[root@vm10-0-0-8 test_data]# top
top - 21:33:55 up 16 days,  6:21,  6 users,  load average: 14.08, 7.45, 4.85
Tasks: 211 total,  17 running, 194 sleeping,   0 stopped,   0 zombie
%Cpu(s): 73.3 us, 26.7 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 32778624 total, 18758856 free,   702964 used, 13316804 buff/cache
KiB Swap:        0 total,        0 free,        0 used. 31479616 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
21761 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21751 root      20   0  113176    388    196 R 100.0  0.0   2:05.11 sh
21752 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21753 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21754 root      20   0  113176    388    196 R 100.0  0.0   2:05.12 sh
21756 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21758 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21759 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21760 root      20   0  113176    388    196 R 100.0  0.0   2:05.13 sh
21762 root      20   0  113176    388    196 R 100.0  0.0   2:05.12 sh
21764 root      20   0  113176    388    192 R 100.0  0.0   2:05.10 sh
21766 root      20   0  113176    388    192 R 100.0  0.0   2:05.13 sh
21755 root      20   0  113176    388    196 R 100.0  0.0   2:05.11 sh
21757 root      20   0  113176    388    196 R 100.0  0.0   2:05.10 sh
21763 root      20   0  113176    388    192 R 100.0  0.0   2:05.11 sh
21765 root      20   0  113176    388    192 R 100.0  0.0   2:05.04 sh