Rocky Linux8.6 : Logwatch ,Disk Usage Check Script

Contents

1. Logwatch
2. Introduce disk usage check script
- 2.1 Scripting
- 2.2 Execution Confirmation

1. Logwatch

① Install

# dnf install logwatch

② Edit configuration file

# cat /usr/share/logwatch/default.conf/logwatch.conf >> /etc/logwatch/conf/logwatch.conf
# vi /etc/logwatch/conf/logwatch.conf

●Per line 45
Insert "#" at the beginning of the "MailTo = root" line and set the email address you want
toreceive notifications to the line below it.
#MailTo = root
MailTo = [Email Address]

●Per line 79 : Set the level of detail for log notifications
#Detail = Low
Detail = High

③ Output Logwatch reports

# logwatch --output stdout

You will get the following message

################### Logwatch 7.6 (01/22/22) ####################
Processing Initiated: Fri May 13 09:41:46 2022
Date Range Processed: yesterday
( 2022-May-12 )
Period is day.
Detail Level of Output: 10
Type of Output/Format: stdout / text
Logfiles for Host: fedora
###########################################################

--------------------- Amavisd-new Begin ------------------------

<中略>

-------------------- Disk Space Begin ------------------------
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/fedora_fedora-root 15G 4.4G 11G 30% /
/dev/nvme0n1p1 1014M 245M 770M 25% /boot
---------------------- Disk Space End -------------------------

###################### Logwatch End #########################

④Test to see if the report arrives at the address you set. Check if you receive a log report email like the one above.

# /etc/cron.daily/0logwatch

2. Introduce disk usage check script

2.1 Scripting

# cd /var/www/system
# vi disk_capacity_check.sh

disk_capacity_check.shの内容

#!/bin/bash

#Designation of e-mail address to be notified
MAIL="<your mailaddress> "

DVAL=`/bin/df / | /usr/bin/tail -1 | /bin/sed 's/^.* $[0-9]*$%.*$/\1/'`

if [ $DVAL -gt 80 ]; then
echo "Disk usage alert: $DVAL %" | mail -s "Disk Space Alert in `hostname`" $MAIL
fi

# chmod 700 disk_capacity_check.sh

2.2 Execution Confirmation

①Check current usage

# df -h

It appears as follows

Filesystem Size Used Avail Use% Mounted on
devtmpfs 873M 0 873M 0% /dev
tmpfs 893M 0 893M 0% /dev/shm
tmpfs 893M 8.8M 884M 1% /run
tmpfs 893M 0 893M 0% /sys/fs/cgroup
/dev/mapper/rl_rocky-root 17G 6.2G 11G 38% /
/dev/nvme0n1p2 1014M 208M 807M 21% /boot
/dev/nvme0n1p1 599M 5.8M 594M 1% /boot/efi
tmpfs 179M 0 179M 0% /run/user/1000

②Create a dummy file to have at least 80% utilization (in the example, it is named "dummyfile" and is about 8G).

# dd if=/dev/zero of=dummyfile bs=1M count=8000

③Re-confirmation

# df -h

Confirmation that it is at least 80%.

④Run disk space check script

# /var/www/system/disk_capacity_check.sh

You will receive an e-mail to the e-mail address you have set up with the body of the message as "Disk usage alert : 86%".

⑤Delete the "dummyfile" you created.

# rm dummyfile

⑥Periodic Execution Setting

# crontab -e
30 2 * * * /var/www/system/disk_capacity_check.sh