Its a shell script which can be used to monitor CPU , Memory , Disk Space of an Linux Server based on the threshold we pass and send email alerts when the usage is above the given threshold . This script also generates list of top processes which takes high cpu and high memory.
Monitoring servers resources is an integral part of every organization . For this we can use Monitoring tools like nagios , zabbix etc .. but here i made use of shell script as a part of learning shell script and can be set as a cronjob so it will periodically check the usage of server resources. This script can be helpful for system engineers/devops engineers for monitoring their server resources.
- The script will monitor filesystem (disk usage) , memory utilization and CPU utilization of Linux Server
- We can set threshold limit (critical & warning limits)
- If the usage goes above mentioned threshold , it will automatically send an email to administrator saying the resource usage is in CRITICAL or WARNING state.
- For CPU and Memory It gives top processes which takes more CPU and memory and send that along with mail.
- If you want to send mail when usage becomes high a mail agent should be installed on the server.Here we can use sendmail.
step1: Get Gmail Id and Password
Step2: login into ubuntu and switch to root using: sudo su -
Step3: Run below commands:
apt-get update -y
apt-get install sendmail mailutils -y
Step4: Create authentication file
cd /etc/mail
mkdir -m 700 authinfo
cd authinfo/
vi gmail
add the below conntent
AuthInfo: "U:root" "I:[email protected]" "P:your-password"
Now edit your mail id and password
Step5: create hash map of the file:
makemap hash gmail < gmail
Step6: Got to /etc/mail and open sendmail.mc
then Add the following lines to sendmail.mc file right above
MAILER_DEFINITIONS:
#GMail settings:
define(`SMART_HOST',`[smtp.gmail.com]')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl
define(`ESMTP_MAILER_ARGS', `TCP $h 587')dnl
define(`confAUTH_OPTIONS', `A p')dnl
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo',`hash -o /etc/mail/authinfo/gmail.db')dnl
Step7: Now run below two command from /etc/mail
make
/etc/init.d/sendmail reload
Step8: Now open https://www.google.com/settings/security/lesssecureapps
and Allow less secure apps: ON
Step9: Verify the test mail using
echo "Demo" | mail -s "Status of Httpd" [email protected]
echo "Demo" | mail -s "Status of Httpd" [email protected] -A demo.txt
- git clone https://github.com/NITHIN-JOHN-GEORGE/disk_cpu_mem_monitor.git
- cd disk_cpu_mem_monitor
- chmod +x resources_cpu_disk_mem.sh
- OPEN THE SCRIPT AND CHANGE THE THRESHOLD VALUES ACCORDING TO OUR ORGANIZATION
DISK_THRESHOLD=<>
CPU_THRESHOLD_WARN=<>
CPU_THRESHOD_CRITICAL=<>
MEM_CRITICAL=<>
MEM_WARNING=<>
-Add a cronjob so it can monitor every 10 mins
# crontab -e
*/10 * * * * <complete path to this script>
