Debian11.3 : Disk Usage Check、Logwatch

Debian11.3_en

2022.06.012025.03.07

Contents

1. Introduce disk usage check script
- 1.1 Scripting
- 1.2 Execution check
2. Log analysis tool logwatch installed

1. Introduce disk usage check script

1.1 Scripting

# cd /opt/script/
# vi disk_capacity_check.sh

1 2	# cd /opt/script/ # vi disk_capacity_check.sh

Contents of disk_capacity_check.sh
Configured to notify when disk usage exceeds 80%.

#!/bin/bash

#Email Address for Notification
MAIL="<E-mail address> "

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

#!/bin/bash

#Email Address for Notification

MAIL="<E-mail address> "

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

# chmod 700 disk_capacity_check.sh

1	# chmod 700 disk_capacity_check.sh

1.2 Execution check

①Check current usage

# df -h

# df -h

It appears as follows

Filesystem      Size  Used Avail Use% Mounted on
udev            959M     0  959M   0% /dev
tmpfs           195M  728K  195M   1% /run
/dev/sda1        19G  3.6G   15G  20% /
tmpfs           975M     0  975M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           195M     0  195M   0% /run/user/1000

Filesystem Size Used Avail Use% Mounted on

udev 959M 0 959M 0% /dev

tmpfs 195M 728K 195M 1% /run

/dev/sda1 19G 3.6G 15G 20% /

tmpfs 975M 0 975M 0% /dev/shm

tmpfs 5.0M 0 5.0M 0% /run/lock

tmpfs 195M 0 195M 0% /run/user/1000

②Create a dummy file (in the example, it is called "dummyfile" and is about 14G) so that the utilization is 80% or more.

# dd if=/dev/zero of=dummyfile bs=1M count=14000

1	# dd if=/dev/zero of=dummyfile bs=1M count=14000

③Re-confirmation

# df -h

# df -h

Run it and make sure it is above 80%.

④Run disk space check script

# /opt/script/disk_capacity_check.sh

1	# /opt/script/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 : 98%".

⑤Delete the "dummyfile" you created.

# rm dummyfile

1	# rm dummyfile

⑥Periodic Execution Setting

# crontab -e
30 2 * * * /opt/script/disk_capacity_check.sh

1 2	# crontab -e 30 2 * * * /opt/script/disk_capacity_check.sh

2. Log analysis tool logwatch installed

2.1 Install logwatch

# apt -y install logwatch

1	# apt -y install logwatch

2.2 Edit logwatch configuration file

①Copy the default configuration file

# cp /usr/share/logwatch/default.conf/logwatch.conf /etc/logwatch/conf/

1	# cp /usr/share/logwatch/default.conf/logwatch.conf /etc/logwatch/conf/

②Change the destination of your email, etc.

# vi /etc/logwatch/conf/logwatch.conf
# Line 50
#MailTo = root  ←　Comment out and add the following
MailTo =<your mailaddress>  ←　Mailing address
# Line 83
Detail = High

# vi /etc/logwatch/conf/logwatch.conf

# Line 50

#MailTo = root ←　Comment out and add the following

MailTo =<your mailaddress> ←　Mailing address

# Line 83

Detail = High

2.3 Creating Directories

There is no directory used by the cache, so create one.

# mkdir /var/cache/logwatch

1	# mkdir /var/cache/logwatch

2.4 operation check

When logwatch is installed, cron is registered by default, so daily report emails are sent
If you want to check it immediately, do the following

# /etc/cron.daily/00logwatch

1	# /etc/cron.daily/00logwatch

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