我们在实际的生产中，linux系统是服务器类的首选，所以下面介绍一下linux系统上一些自带的监控小命令。
top ：动态的查看进程，默认每五秒自动更新一下
[root@www nagios-plugins-2.1.1]# top
top - 01:27:11 up 13:08, 4 users, load average: 0.00, 0.00, 0.00
Tasks: 182 total, 1 running, 181 sleeping, 0 stopped, 0 zombie
Cpu(s): 2.5%us, 1.0%sy, 0.0%ni, 96.2%id, 0.2%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 2039792k total, 1593056k used, 446736k free, 70484k buffers
Swap: 4095992k total, 0k used, 4095992k free, 995488k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
33701 root 20 0 192m 4848 948 S 1.3 0.2 0:20.08 snmpd
34034 python 20 0 690m 70m 26m S 1.3 3.5 0:48.24 firefox
62101 root 20 0 14936 1128 796 R 1.3 0.1 0:00.26 top
1 root 20 0 19252 1432 1156 S 0.0 0.1 0:04.34 init
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
4 root 20 0 0 0 0 S 0.0 0.0 0:00.02 ksoftirqd/0
5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
6 root 20 0 0 0 0 S 0.0 0.0 0:00.62 events/0
7 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuset
8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 khelper
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 netns
10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 async/mgr
11 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pm
12 root 20 0 0 0 0 S 0.0 0.0 0:00.00 sync_supers
13 root 20 0 0 0 0 S 0.0 0.0 0:00.01 bdi-default
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kintegrityd/0
15 root 20 0 0 0 0 S 0.0 0.0 0:01.46 kblockd/0
w ：谁登录了你的系统，在做什么？
[root@www nagios-plugins-2.1.1]# w
01:27:33 up 13:08, 4 users, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
python tty1 :0 Thu12 13:08m 40.28s 0.24s pam: gdm-password
python pts/0 :0.0 Thu12 4:38m 0.04s 0.76s /usr/bin/gnome-terminal -x /bin/sh -c cd '/home/python/D
python pts/1 :0.0 22:51 2:36m 0.02s 0.02s /bin/bash -l
root pts/3 192.168.1.106 22:51 0.00s 3.55s 0.01s w
uptime ：系统运行了多久
[root@www nagios-plugins-2.1.1]# uptime
01:28:17 up 13:09, 4 users, load average: 0.00, 0.00, 0.00
ps ：查看进程
[root@www nagios-plugins-2.1.1]# ps
PID TTY TIME CMD
33642 pts/3 00:00:00 bash
33827 pts/3 00:00:00 mysqld_safe
34368 pts/3 00:00:00 su
34561 pts/3 00:00:00 su
34565 pts/3 00:00:00 bash
62117 pts/3 00:00:00 ps
iostat：cpu平均负载，硬盘活动信息
[root@www nagios-plugins-2.1.1]# iostat
Linux 2.6.32-71.el6.x86_64 (www.fwc.com) 12/18/2015 x86_64 (1 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
2.45 0.00 1.13 0.19 0.00 96.23
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 2.28 18.65 54.13 884498 2566522
vmstat：系统活动、系统信息、
[root@www nagios-plugins-2.1.1]# vmstat
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
1 0 0 444520 73004 996180 0 0 9 26 55 56 2 1 96 0 0
[root@www nagios-plugins-2.1.1]#
sar：搜集报告系统活动
[root@www nagios-plugins-2.1.1]# sar
Linux 2.6.32-71.el6.x86_64 (www.fwc.com) 12/18/2015 x86_64 (1 CPU)
12:00:02 AM CPU %user %nice %system %iowait %steal %idle
12:10:01 AM all 3.45 0.00 1.58 0.06 0.00 94.91
12:20:01 AM all 13.87 0.00 4.72 0.05 0.00 81.35
12:30:01 AM all 25.99 0.00 12.22 0.17 0.00 61.62
12:40:01 AM all 1.59 0.00 1.21 0.04 0.00 97.16
12:50:02 AM all 0.47 0.00 1.02 0.03 0.00 98.49
01:00:01 AM all 0.40 0.00 0.96 0.02 0.00 98.62
01:10:02 AM all 0.46 0.00 1.05 0.05 0.00 98.44
01:20:01 AM all 0.45 0.00 0.98 0.06 0.00 98.50
01:30:01 AM all 0.47 0.00 1.11 0.07 0.00 98.34
01:40:01 AM all 0.43 0.00 0.93 0.04 0.00 98.59
01:50:02 AM all 0.38 0.00 0.88 0.03 0.00 98.71
02:00:02 AM all 0.41 0.00 0.87 0.03 0.00 98.69
02:10:01 AM all 0.47 0.00 0.99 0.02 0.00 98.52
Average: all 3.74 0.00 2.19 0.05 0.00 94.02
ss ：网络相关信息
[root@www nagios-plugins-2.1.1]# ss
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 0 192.168.1.112:44540 208.31.254.33:http
ESTAB 0 164 192.168.1.112:ssh 192.168.1.106:51503
[root@www nagios-plugins-2.1.1]#
netstat：网络相关信息
[root@www nagios-plugins-2.1.1]# netstat |head
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 bogon:44540 208.31.254.33:http ESTABLISHED
tcp 0 52 bogon:ssh bogon:51503 ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ] DGRAM 9326 @/org/kernel/udev/udevd
unix 2 [ ] DGRAM 12765 @/org/freedesktop/hal/udev_event
unix 29 [ ] DGRAM 12179 /dev/log
unix 2 [ ] DGRAM 176485
[root@www nagios-plugins-2.1.1]#
因为太多了，只取头部。