Shell Scripts monitor Linux system memory usage (not using Nagios to monitor Linux) _linux shell

First, install the following Linux mail client msmtp software (similar to a foxmail tool)
1. Download and install:

Copy Code code as follows:

# tar JXVF msmtp-1.4.16.tar.bz2
# CD msmtp-1.4.16
#./configure--PREFIX=/USR/LOCAL/MSMTP
# make
# make Install

2, create MSMTP configuration file and log file (host for the mail domain name, mail username test, password 123456)

Copy Code code as follows:

# Vim ~/.MSMTPRC
Account Default
Host 126.com
From test@126.com
Auth Login
User test
Password 123456
LogFile ~/.msmtp.log
# chmod 600~/.MSMTPRC
# Touch ~/.msmtp.log

3, Mutt Installation configuration: (General Linux has the default installation mutt)

Copy Code code as follows:

# Vim ~/.MUTTRC
Set sendmail= "/usr/local/msmtp/bin/msmtp"
Set Use_from=yes
Set realname= "Memory"
Set from=test@126.com
Set Envelope_from=yes
Set Rfc2047_parameters=yes
Set charset= "Utf-8"

4, the mail sends the test (S-mail title, a table plus annex)

Copy Code code as follows:

# echo "message content 123456" | Mutt-s "Message header test Message"-a/scripts/test.txttest@126.com

Monitoring system memory using free command:

1, use the free command to view the Linux system memory usage: (in m)

Copy Code code as follows:

# free-m

(Execution results are the following style)

Copy Code code as follows:

Total used free Sharedbuffers Cached
mem:3952 34145380168484
-/+ buffers/cache:2760 1191
SWAP:8191 86 8105

2, view the Intercept the remaining memory Free value command:

(1) Free value of physical memory: # Free-m | grep Mem | awk ' {print $} '
(2) Free value of the buffer: # Free-m | grep-| awk ' {print $} '
(3) Swap partition Free value: # Free-m | grep Swap | awk ' {print $} '

3, write the Memory monitoring script file:

Copy Code code as follows:

# vim/scripts/free-mem.sh
#!/bin/bash
#使用free命令监控linux系统内存变化

#取系统当前时间 (write file as append >>)
Date >>/scripts/date-time.txt

#抓取物理内存free值 (write file as append >>)
echo mem-free: ' Free-m | grep Mem | awk ' {print $} ' M >>/scripts/mem-free.txt

#抓取缓冲区的free值 (write file as append >>)
echo buffers/cache-free: ' Free-m | grep-| awk ' {print $} ' m>>/scripts/buffers-free.txt

#抓取Swap分区free值 (write file as append >>)
echo swap-free: ' Free-m | grep Swap | awk ' {print $} ' m>>/scripts/swap-free.txt

#逐行连接上面的时间和内存相关行数据 (each time the file is rewritten >)
Paste/scripts/date-time.txt/scripts/mem-free.txt/scripts/buffers-free.txt/scripts/swap-free.txt >/scripts/ Freemem.txt
# chmod a+x/scripts/free-mem.sh
#/scripts/free-mem.sh
4, view the memory monitoring results file:
# Cat/scripts/freemem.txt
5. Write free result file mail Send script:
# vim/scripts/sendmail-mem.sh
#!/bin/bash
#把生成的freemem. txt file is sent to the user by mail

#提取本服务器的IP地址信息
ip= ' Ifconfig eth0 | grep "inet addr" | Cut-f 2-d ":" | Cut-f 1-d "" '

#提取当前日期时间
today= ' date-d ' 0 day ' +%y year%m month%d '

#发送内存监控结果邮件
echo "This is the memory monitoring report for the $IP server $today, please download the attachment." " | Mutt-s "$IP Server $today Memory Monitoring Report"-a/scripts/freemem.txt test@126.com
# chmod a+x/scripts/sendmail-mem.sh

Third, the monitoring system swap partition Swap, when the use of more than 80% of the time to send a warning message:

Copy Code code as follows:

# vim/scripts/swap-warning.sh
#!/bin/bash

#提取本服务器的IP地址信息
ip= ' Ifconfig eth0 | grep "inet addr" | Cut-f 2-d ":" | Cut-f 1-d "" '

#系统分配的交换分区总量
Swap_total= ' Free-m | grep Swap | awk ' {print$2} '

#当前剩余的交换分区free大小
Swap_free= ' Free-m | grep Swap | awk ' {print$4} '

#当前已使用的交换分区used大小
Swap_used= ' Free-m | grep Swap | awk ' {print$3} '

if (($swap _used!= 0)); Then

#如果交换分区已被使用, calculates the percentage of the total amount of free for the current remaining swap partition, in decimal notation, to make an integer digit 0 before the decimal point
Swap_per=0 ' echo ' scale=2 $swap _free/$swap _total "| BC '

#设置交换分区的告警值为20% (that is, when using more than 80% alarm).
swap_warn=0.20

#当前剩余交换分区百分比与告警值进行比较 (1 is returned when it is greater than the alarm value (i.e., more than 20%), and 0 is returned when less than (i.e., less than 20% remaining)
swap_now= ' expr $swap _per \> $swap _warn '

#如果当前交换分区使用超过80% (that is, the remaining is less than 20%, the return value above equals 0), send an email alert immediately
if (($swap _now = 0)); Then
echo "$IP server swap partition is left $swap _free M unused, remaining less than 20%, the utilization rate has exceeded 80%, please deal with it in time. " | Mutt-s "$IP server memory Alert" test@126.com
Fi

Fi
# chmod a+x/scripts/swap-warning.sh

Four, join the task plan: Memory every 10 minutes of detection, alarm is immediately send mail (10 minutes), memory test results mail every morning 8 point send a

Copy Code code as follows:

# CRONTAB-E

*/10 * * * */scripts/free-mem.sh
*/10 * * * */scripts/swap-warning.sh
0 8 * * */scripts/sendmail-mem.sh

# Service Crond Restart