Contents
Tripwire
1.Download and installation
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# cd /usr/local/src # wget https://rpmfind.net/linux/epel/9/Everything/x86_64/Packages/t/tripwire-2.4.3.7-13.el9.x86_64.rpm # rpm -Uvh tripwire-2.4.3.7-13.el9.x86_64.rpm |
2.Passphrase setting
Set site passphrase and local passphrase
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# tripwire-setup-keyfiles |
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---------------------------------------------- The Tripwire site and local passphrases are used to sign a variety of files, such as the configuration, policy, and database files. Passphrases should be at least 8 characters in length and contain both letters and numbers. See the Tripwire manual for more information. ---------------------------------------------- Creating key files... (When selecting a passphrase, keep in mind that good passphrases typically have upper and lower case letters, digits and punctuation marks, and are at least 8 characters in length.) Enter the site keyfile passphrase: ←Enter any "Site Passphrase" Verify the site keyfile passphrase: ←Enter "Site Passphrase" again Generating key (this may take several minutes)...Key generation complete. (When selecting a passphrase, keep in mind that good passphrases typically have upper and lower case letters, digits and punctuation marks, and are at least 8 characters in length.) Enter the local keyfile passphrase: ←Enter any "local passphrase" Verify the local keyfile passphrase: ←Enter "Local Passphrase" again Generating key (this may take several minutes)...Key generation complete. ---------------------------------------------- Signing configuration file... Please enter your site passphrase: ←Enter "Site Passphrase" Wrote configuration file: /etc/tripwire/tw.cfg A clear-text version of the Tripwire configuration file: /etc/tripwire/twcfg.txt has been preserved for your inspection. It is recommended that you move this file to a secure location and/or encrypt it in place (using a tool such as GPG, for example) after you have examined it. ---------------------------------------------- Signing policy file... Please enter your site passphrase: ←Enter "Site Passphrase" Wrote policy file: /etc/tripwire/tw.pol A clear-text version of the Tripwire policy file: /etc/tripwire/twpol.txt ~omission~ default values from the current configuration file are used. |
3.Tripwire Configuration
①Configuration File Edit
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# vi /etc/tripwire/twcfg.txt ●Per line 9 Add "#" at the beginning of the line and "LOOSEDIRECTORYCHECKING =true" on the line below it ●Per line 12 Add "#" at the beginning of the line and "REPORTLEVEL =4" on the line below it. Level 4 provides the most detailed report of the five levels from "0" to "4". #REPORTLEVEL =3 REPORTLEVEL =4 |
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# twadmin -m F -c /etc/tripwire/tw.cfg -S /etc/tripwire/site.key /etc/tripwire/twcfg.txt Please enter your site passphrase: ←Enter site passphrase" Wrote configuration file: /etc/tripwire/tw.cfg |
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# rm -f /etc/tripwire/twcfg.txt |
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# cd /etc/tripwire/ # vi twpolmake.pl |
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#!/usr/bin/perl # Tripwire Policy File customize tool # $POLFILE=$ARGV[0]; open(POL,"$POLFILE") or die "open error: $POLFILE" ; my($myhost,$thost) ; my($sharp,$tpath,$cond) ; my($INRULE) = 0 ; while (<POL>) { chomp; if (($thost) = /^HOSTNAME\s*=\s*(.*)\s*;/) { $myhost = `hostname` ; chomp($myhost) ; if ($thost ne $myhost) { $_="HOSTNAME=\"$myhost\";" ; } } elsif ( /^{/ ) { $INRULE=1 ; } elsif ( /^}/ ) { $INRULE=0 ; } elsif ($INRULE == 1 and ($sharp,$tpath,$cond) = /^(\s*\#?\s*)(\/\S+)\b(\s+->\s+.+)$/) { $ret = ($sharp =~ s/\#//g) ; if ($tpath eq '/sbin/e2fsadm' ) { $cond =~ s/;\s+(tune2fs.*)$/; \#$1/ ; } if (! -s $tpath) { $_ = "$sharp#$tpath$cond" if ($ret == 0) ; } else { $_ = "$sharp$tpath$cond" ; } } print "$_\n" ; } close(POL) ; |
⑤Policy File Optimizations
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# perl /etc/tripwire/twpolmake.pl /etc/tripwire/twpol.txt > /etc/tripwire/twpol.txt.new |
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# twadmin -m P -c /etc/tripwire/tw.cfg -p /etc/tripwire/tw.pol -S /etc/tripwire/site.key /etc/tripwire/twpol.txt.new Please enter your site passphrase: ←Enter site passphrase Wrote policy file: /etc/tripwire/tw.pol |
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# tripwire -m i -s -c /etc/tripwire/tw.cfg Please enter your local passphrase: ←Enter local passphrase |
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Create test files # echo test > /root/test.txt |
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Check Tripwire operation # tripwire -m c -s -c /etc/tripwire/tw.cfg OK if it appears as follows Open Source Tripwire(R) 2.4.3.7 Integrity Check Report Report generated by: root Report created on: Thu 17 Nov 2022 09:13:28 AM JST Database last updated on: Never =============================================================================== Report Summary: =============================================================================== Host name: Lepard Host IP address: 192.168.11.83 Host ID: None Policy file used: /etc/tripwire/tw.pol Configuration file used: /etc/tripwire/tw.cfg Database file used: /var/lib/tripwire/Lepard.twd Command line used: tripwire -m c -s -c /etc/tripwire/tw.cfg =============================================================================== Rule Summary: =============================================================================== ------------------------------------------------------------------------------- Section: Unix File System ------------------------------------------------------------------------------- Rule Name Severity Level Added Removed Modified --------- -------------- ----- ------- -------- User binaries 66 0 0 0 Tripwire Binaries 100 0 0 0 Libraries 66 0 0 0 Operating System Utilities 100 0 0 0 File System and Disk Administraton Programs 100 0 0 0 Kernel Administration Programs 100 0 0 0 Networking Programs 100 0 0 0 System Administration Programs 100 0 0 0 Hardware and Device Control Programs 100 0 0 0 System Information Programs 100 0 0 0 (/sbin/runlevel) Application Information Programs 100 0 0 0 (/sbin/rtmon) Critical Utility Sym-Links 100 0 0 0 Shell Binaries 100 0 0 0 Critical system boot files 100 0 0 0 * Tripwire Data Files 100 1 0 0 System boot changes 100 0 0 0 OS executables and libraries 100 0 0 0 Security Control 100 0 0 0 Login Scripts 100 0 0 0 Critical configuration files 100 0 0 0 * Root config files 100 1 0 0 Invariant Directories 66 0 0 0 Temporary directories 33 0 0 0 Critical devices 100 0 0 0 (/proc/kcore) Total objects scanned: 33787 Total violations found: 2 =============================================================================== Object Summary: =============================================================================== ------------------------------------------------------------------------------- # Section: Unix File System ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Rule Name: Tripwire Data Files (/var/lib/tripwire) Severity Level: 100 ------------------------------------------------------------------------------- Added: "/var/lib/tripwire/Lepard.twd" ------------------------------------------------------------------------------- Rule Name: Root config files (/root) Severity Level: 100 ------------------------------------------------------------------------------- Added: "/root/test.txt" =============================================================================== Error Report: =============================================================================== No Errors ------------------------------------------------------------------------------- *** End of report *** Open Source Tripwire 2.4 Portions copyright 2000-2018 Tripwire, Inc. Tripwire is a registered trademark of Tripwire, Inc. This software comes with ABSOLUTELY NO WARRANTY; for details use --version. This is free software which may be redistributed or modified only under certain conditions; see COPYING for details. All rights reserved. |
Delete test files
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# rm -f /root/test.txt |
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# cd /var/www/system # vi tripwire.sh |
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#!/bin/bash PATH=/usr/sbin:/usr/bin:/bin:/usr/local/tripwire/sbin # Passphrase setting LOCALPASS= ←local passphrase SITEPASS= ←site passphrase cd /etc/tripwire # Tripwire check run tripwire -m c -s -c tw.cfg|mail -s "Tripwire(R) Integrity Check Report in `hostname`" root # Policy File Update twadmin -m p -c tw.cfg -p tw.pol -S site.key > twpol.txt perl twpolmake.pl twpol.txt > twpol.txt.new twadmin -m P -c tw.cfg -p tw.pol -S site.key -Q $SITEPASS twpol.txt.new > /dev/null rm -f twpol.txt* *.bak # Database Update rm -f /usr/local/tripwire/lib/tripwire/*.twd* tripwire -m i -s -c tw.cfg -P $LOCALPASS |
⑨Tripwire Autorun Script Execution Settings
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# chmod 700 tripwire.sh Add to cron # crontab -e 0 3 * * * /var/www/system/tripwire.sh |
Reference: Script for reporting results by e-mail
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#!/bin/bash PATH=/usr/sbin:/usr/bin:/bin:/usr/local/tripwire/sbin # Passphrase setting LOCALPASS=xxxxx # local passphrase SITEPASS=xxxxx # site passphrase #Specify e-mail address for notification MAIL="<your mailaddress> " cd /etc/tripwire # Tripwire check run tripwire -m c -s -c tw.cfg|mail -s "Tripwire(R) Integrity Check Report in `hostname`" $MAIL # Policy File Update twadmin -m p -c tw.cfg -p tw.pol -S site.key > twpol.txt perl twpolmake.pl twpol.txt > twpol.txt.new twadmin -m P -c tw.cfg -p tw.pol -S site.key -Q $SITEPASS twpol.txt.new > /dev/null rm -f twpol.txt* *.bak # Database update rm -f /usr/local/tripwire/lib/tripwire/*.twd* tripwire -m i -s -c tw.cfg -P $LOCALPASS |
Confirmation that the results of the tripwire execution are notified to the specified e-mail address
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# /var/www/system/tripwire.sh |
Chkrootkit
①Download and install chkrootkit
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# cd /usr/local/src # wget https://launchpad.net/chkrootkit/main/0.55/+download/chkrootkit-0.55.tar.gz # tar xvf chkrootkit-0.55.tar.gz |
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# mkdir -p /root/bin # mv chkrootkit-0.55/chkrootkit /root/bin |
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# chkrootkit | grep INFECTED If nothing is displayed, no problem. |
④Create chkrootkit periodic execution script and change permissions
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Create chkrootkit execution script in a directory where it is automatically executed daily # vi /etc/cron.daily/chkrootkit |
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#!/bin/bash PATH=/usr/bin:/bin:/root/bin LOG=/tmp/$(basename ${0}) # Run chkrootkit chkrootkit > $LOG 2>&1 # log output cat $LOG | logger -t $(basename ${0}) # SMTPS bindshell false positive response if [ ! -z "$(grep 465 $LOG)" ] && \ [ -z $(/usr/sbin/lsof -i:465|grep bindshell) ]; then sed -i '/465/d' $LOG fi # Support for Suckit false positives when updating upstart package if [ ! -z "$(grep Suckit $LOG)" ] && \ [ -z "$(rpm -V `rpm -qf /sbin/init`)" ]; then sed -i '/Suckit/d' $LOG fi # Send mail to root only when rootkit is detected [ ! -z "$(grep INFECTED $LOG)" ] && \ grep INFECTED $LOG | mail -s "chkrootkit report in `hostname`" root |
Add execution permission to chkrootkit execution script
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# chmod 700 /etc/cron.daily/chkrootkit |
Back up these commands.
If necessary, run chkrootkit with the backed up command
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# cd /root # mkdir /root/chkrootkit_cmd # cp `which --skip-alias awk cut echo egrep find head id ls netstat ps strings sed ssh uname` chkrootkit_cmd/ # ls -l /root/chkrootkit_cmd/ total 2636 -rwxr-xr-x 1 root root 714928 Oct 27 12:17 awk -rwxr-xr-x 1 root root 49440 Oct 27 12:17 cut -rwxr-xr-x 1 root root 36816 Oct 27 12:17 echo -rwxr-xr-x 1 root root 32 Oct 27 12:17 egrep -rwxr-xr-x 1 root root 292768 Oct 27 12:17 find -rwxr-xr-x 1 root root 45336 Oct 27 12:17 head -rwxr-xr-x 1 root root 41144 Oct 27 12:17 id -rwxr-xr-x 1 root root 141944 Oct 27 12:17 ls -rwxr-xr-x 1 root root 161648 Oct 27 12:17 netstat -rwxr-xr-x 1 root root 145320 Oct 27 12:17 ps -rwxr-xr-x 1 root root 116744 Oct 27 12:17 sed -rwxr-xr-x 1 root root 851424 Oct 27 12:17 ssh -rwxr-xr-x 1 root root 33176 Oct 27 12:17 strings -rwxr-xr-x 1 root root 32912 Oct 27 12:17 uname |
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# chkrootkit -p /root/chkrootkit_cmd | grep INFECTED |
If nothing is displayed, no problem.
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# tar zcvf chkrootkit_cmd.tar.gz chkrootkit_cmd chkrootkit_cmd/ chkrootkit_cmd/awk chkrootkit_cmd/cut chkrootkit_cmd/echo chkrootkit_cmd/egrep chkrootkit_cmd/find chkrootkit_cmd/head chkrootkit_cmd/id chkrootkit_cmd/ls chkrootkit_cmd/netstat chkrootkit_cmd/ps chkrootkit_cmd/strings chkrootkit_cmd/sed chkrootkit_cmd/ssh chkrootkit_cmd/uname |
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# ls -l total 121512 -rw-r--r--. 1 root root 0 Nov 16 15:09 '=' -rw-------. 1 root root 1319 Nov 16 12:40 anaconda-ks.cfg drwxr-xr-x. 2 root root 4096 Nov 17 09:19 bin drwxr-xr-x. 2 root root 4096 Nov 17 09:23 chkrootkit_cmd -rw-r--r--. 1 root root 1222072 Nov 17 09:24 chkrootkit_cmd.tar.gz | | |
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# echo|mail -a chkrootkit_cmd.tar.gz -s chkrootkit_cmd.tar.gz root |
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# rm -f chkrootkit_cmd.tar.gz |
Logwatch
①Install
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# dnf install logwatch |
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# cat /usr/share/logwatch/default.conf/logwatch.conf >> /etc/logwatch/conf/logwatch.conf # vi /etc/logwatch/conf/logwatch.conf |
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●Per line 51 Set "MailTo = root" as a comment and set the email address you want to receive notifications to the line below it. #MailTo = root MailTo = [Mail address] ●Per line 84 : Set the level of detail for log notifications #Detail = Low Detail = High |
③Output Logwatch reports
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# logwatch --output stdout |
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################### Logwatch 7.5.5 (01/22/21) #################### Processing Initiated: Thu Nov 17 09:36:10 2022 Date Range Processed: yesterday ( 2022-Nov-16 ) Period is day. Detail Level of Output: 10 Type of Output/Format: stdout / text Logfiles for Host: Lepard ################################################################# --------------------- Kernel Audit Begin ------------------------ Number of audit daemon starts: 1 Number of audit initializations: 1 **Unmatched Entries** auditd[748]: audit dispatcher initialized with q_depth=1200 and 1 active plugins: 1 Time(s) ---------------------- Kernel Audit End ------------------------- <中略> --------------------- Disk Space Begin ------------------------ Filesystem Size Used Avail Use% Mounted on /dev/mapper/rl-root 17G 5.0G 13G 30% / /dev/nvme0n1p1 1014M 270M 745M 27% /boot ---------------------- Disk Space End ------------------------- --------------------- lm_sensors output Begin ------------------------ No sensors found! Make sure you loaded all the kernel drivers you need. Try sensors-detect to find out which these are. ---------------------- lm_sensors output 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.
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# /etc/cron.daily/0logwatch |
DiCE
Whenever the global IP changes, which happens when the network is disconnected or the router is disconnected and rebooted, the dynamic DNS must be accessed to inform the user that the global IP has changed. DiCE does this automatically!
①Download and install Dice
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# cd /usr/local/bin # wget http://www.hi-ho.ne.jp/yoshihiro_e/dice/diced01914.tar.gz # tar -xzvf diced01914.tar.gz # cd /usr/local/bin/DiCE |
DiCE output characters are EUC and therefore garbled; install nkf to convert to UTF-8
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# dnf install nkf |
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# dnf install glibc.i686 |
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# cd /usr/local/bin/DiCE # ./diced | nkf -uw |
When the DNS service is VALUEDOMAIN
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# ./diced | nkf -uw : add DynamicDNSサービス名を入力してください "?"で対応しているサービスを一覧表示します (P)戻る >VALUEDOMAIN ドメイン名を入力してください "?"でドメイン一覧を表示します (P)戻る ><ドメイン名> ホスト名を入力してください (P)戻る ><ホスト名> ログインユーザ名を入力してください (P)戻る ><ユーザー名> ←VALUEDOMAINに登録したユーザー名 ログインパスワードを入力してください (P)戻る ><passwd> ←VALUEDOMAINにログインするパスワード 登録するIPアドレスを入力してください 空白にすると現在のIPアドレスを自動検出します (P)戻る >空白 このイベントに題名を付けてください (P)戻る >xxxxxxxxx(適当に付ける) 実行する頻度を指定してください (番号入力) (0)1回のみ (1)1日1回 (2)1週間に1回 (3)1ヵ月に1回 (4)その他の周期 (5)IPアドレス変化時 (6)起動時 (P)戻る >5 (任意に決める) IPアドレスがあまり変化しない環境の場合、更新せずに一定期間を過ぎると アカウントを削除されてしまうことがあります IPアドレスの変化が無い時に実行する間隔を指定してください (0)7日毎 (1)14日毎 (2)21日毎 (3)28日毎 (4)35日毎 (5)56日毎 (6)84日毎 (P)戻る >0(任意に決める) このイベントを有効にしますか? (Y/N) (イベントの有効/無効は"EN/DIS"コマンドで切替えられます) >y イベントを保存しますか? (Y/N) >y イベントの確認 :list (No.) (イベント名) (スケジュール) (次回予定) 0 * xxxxxxxxx IPアドレス変化時 (7日毎) 01/27 06:27ー 手動実行 :ex 0 + 1/20 6:33 にddns_valuedomainが実行されました IPアドレスを更新しました :exit |
⑤Automatic execution of Dice
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# /usr/local/bin/DiCE/diced -d -l -=-=- DiCE DynamicDNS Client -=-=-= Version 0.19 for Japanese Copyright(c) 2001 sarad DiCE Daemon Started !! |
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# ps aux | grep diced root 150637 0.4 0.0 5776 124 ? Ss 14:40 0:00 /usr/local/bin/DiCE/diced -d -l root 150708 94.7 0.1 5776 1796 ? Rs 14:40 0:09 /usr/local/bin/DiCE/diced -d -l root 150882 0.0 0.1 6412 2008 pts/0 S+ 14:40 0:00 grep --color=auto diced |
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# vi /etc/rc.local /usr/local/bin/DiCE/diced -d -l (Add) |
There is no English version of DiCE.
Since the above DiCE is only available in Japanese and is old and has not been updated, I have prepared a shell script to update it.
I'm not sure if it will work, but I'll try it on a trial basis.
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# vi /var/www/system/valuedomain_updqte.sh #/bin/bash#VARIABLES DOMAINNAME="[Domain name]" PASSWORD="[Password]" HOSTNAME="*" MYIP="" # External IP Acquisition MYIP=`wget -q -O - "https://dyn.value-domain.com/cgi-bin/dyn.fcg?ip"` sleep 5 # update process wget -q -O - "https://dyn.value-domain.com/cgi-bin/dyn.fcg?d=$DOMAINNAME&p=$PASSWORD&h=$HOSTNAME&i=$MYIP" |
With crontab -e, add the following to update periodically
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# crontab -e */30 * * * * /var/www/system/valuedomain_updqte.sh |
Introduce disk usage check script
3.1 Script Creation
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# cd /var/www/system # vi disk_capacity_check.sh |
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#!/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 |
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# chmod 700 disk_capacity_check.sh |
3.2 Execution Confirmation
①Check current usage rates
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# df -h |
It appears as follows
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Filesystem Size Used Avail Use% Mounted on devtmpfs 856M 0 856M 0% /dev tmpfs 875M 0 875M 0% /dev/shm tmpfs 350M 9.2M 341M 3% /run /dev/mapper/ml-root 17G 5.2G 11G 33% / /dev/nvme0n1p1 974M 178M 729M 20% /boot tmpfs 175M 0 175M 0% /run/user/1000 |
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# dd if=/dev/zero of=dummyfile bs=1M count=9000 |
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# df -h |
④Run check scripts
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# /var/www/system/disk_capacity_check.sh |
You will receive an email to the email address you have set up, stating something like "Disk usage alert: 89 %".
⑤Delete "dummyfile"
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# rm dummyfile |
⑥Periodic Execution Setting
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# crontab -e 30 2 * * * /var/www/system/disk_capacity_check.sh |