unicornist · September 3, 2024 09:38 · Nov 15, 2022 · Sep 7, 2021 · Jul 16, 2021 · Jul 15, 2021
diff --git a/Centos7.md b/Centos7.md
@@ -21,7 +21,7 @@ yum -y install git
 to check/set server timezone and enable NTP time sync:
 
 ```bash
-timedatectl set-timezone UTC #Asia/Tehran
+timedatectl set-timezone UTC #Asia/Dubai
 timedatectl set-ntp on
 systemctl enable --now chronyd
 ## check status
@@ -34,12 +34,12 @@ timedatectl
 1.Setup a Proxy (if needed)
 ---
 
-Replace `USER` and `PASS` for proxy settings.
+Replace `USER` and `PASS` and `PROXY` for proxy settings.
 
 ```bash
-export https_proxy=http://USER:PASS@us.mybestport.com:443/
+export https_proxy=http://USER:PASS@PROXY:443/
 vim /etc/yum.conf
-#proxy=http://us.mybestport.com:443/
+#proxy=http://PROXY:443/
 #proxy_username=USER
 #proxy_password=PASS
 ```

diff --git a/Centos7.md b/Centos7.md
@@ -158,6 +158,8 @@ npm i -g gulp gulp-cli bower
 4.MongoDB
 ---
 
+You can make a yum repo config and install everything with a single command like:
+
 ```bash
 vim /etc/yum.repos.d/mongodb-org-4.4.repo
 ```
@@ -176,13 +178,26 @@ then press <kbd>esc</kbd> then type `:wq` and  press <kbd>enter</kbd>
 
 ```bash
 yum install -y mongodb-org
-#yum install -y https://repo.mongodb.org/yum/redhat/7/mongodb-org/3.6/x86_64/RPMS/mongodb-org-3.6.4-1.el7.x86_64.rpm
-service mongod start
-chkconfig mongod on
+```
+
+**OR** you can install all mongodb packages separately directly with their RPM links found in [this link](https://repo.mongodb.org/yum/redhat/7/mongodb-org/). PS: You have to install them in order to prevent dependancy errors.
+
+```bash
+yum install -y https://repo.mongodb.org/yum/redhat/7/mongodb-org/???/x86_64/RPMS/mongodb-org-??????.el7.x86_64.rpm
+```
+
+After installing, run and check like this:
+
+```bash
+systemctl start mongod
+systemctl enable mongod
+#mongo
+mongosh
 ```
 
 Please also consider disabling Transparent Huge Pages for better performance: https://docs.mongodb.com/manual/tutorial/transparent-huge-pages/
 
+
 5.Redis
 ---
 

diff --git a/LAMP.md b/LAMP.md
@@ -82,9 +82,21 @@ systemctl restart mysqld
 #mysql> show databases;
 ```
 
-3.PHP 7.4
+For creating a new DB and user and grant permissions, replace `db_name`,  `newuser`,  `password`, and possibly `localhost` in the following commands, and run it.
+
+```bash
+mysql -u root -p
+CREATE DATABASE db_name;
+CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';
+GRANT ALL PRIVILEGES ON db_name.* TO 'newuser'@'localhost';
+FLUSH PRIVILEGES;
+```
+
+3.PHP
 ---
 
+To install PHP 7.4 with a bunch of commonly usded modules, run the following:
+
 ```bash
 yum install -y https://rpms.remirepo.net/enterprise/remi-release-7.rpm
 yum-config-manager --enable remi-php74
@@ -98,16 +110,15 @@ systemctl restart httpd
 #rm /var/www/html/info.php
 ```
 
-4.PHPMyAdmin
----
+### PHPMyAdmin
 
 ```bash
 yum install -y phpmyadmin
 systemctl restart httpd
 ```
 
 
-5.FTP Server
+4.FTP Server
 ---
 
 ```bash

diff --git a/LAMP.md b/LAMP.md
@@ -8,6 +8,47 @@ yum install -y httpd
 systemctl start httpd
 systemctl enable httpd
 #curl http://127.0.0.1/
+setsebool -P httpd_unified 1
+chmod -R 755 /var/www
+mkdir /etc/httpd/sites-available /etc/httpd/sites-enabled
+echo 'IncludeOptional sites-enabled/*.conf' >> /etc/httpd/conf/httpd.conf
+```
+
+Now for each vistual server (e.g. `example.com` hostname) do the following
+
+```bash
+mkdir -p /var/www/example.com/html
+mkdir -p /var/www/example.com/log
+semanage fcontext -a -t httpd_log_t "/var/www/example.com/log(/.*)?"
+restorecon -R -v /var/www/example.com/log
+ls -dZ /var/www/example.com/log
+echo 'example.com' > /var/www/example.com/html/index.html
+vim /etc/httpd/sites-available/example.com.conf
+```
+
+now in the config file you can use a minimal config like this:
+
+```
+<VirtualHost *:80>
+    ServerName www.example.com
+    ServerAlias example.com
+    DocumentRoot /var/www/example.com/html
+    ErrorLog /var/www/example.com/log/error.log
+    CustomLog /var/www/example.com/log/requests.log combined
+</VirtualHost>
+```
+
+And finally with a sudoer user run the following, or if already su replace $USER with a username manually:
+
+```bash
+sudo chown -R $USER:$USER /var/www/example.com/html
+```
+
+And for enabling any site
+
+```bash
+ln -s /etc/httpd/sites-available/example.com.conf /etc/httpd/sites-enabled/example.com.conf
+systemctl restart httpd
 ```
 
 2.MySQL
@@ -55,4 +96,27 @@ echo '<?php phpinfo(); ?>' > /var/www/html/info.php
 systemctl restart httpd
 #curl http://127.0.0.1/info.php
 #rm /var/www/html/info.php
+```
+
+4.PHPMyAdmin
+---
+
+```bash
+yum install -y phpmyadmin
+systemctl restart httpd
+```
+
+
+5.FTP Server
+---
+
+```bash
+yum install -y vsftpd
+systemctl start vsftpd
+systemctl enable vsftpd
+cp /etc/vsftpd/vsftpd.conf /etc/vsftpd/vsftpd.conf.default
+vim /etc/vsftpd/vsftpd.conf
+#anonymous_enable=NO
+vim /etc/vsftpd/user_list
+systemctl restart vsftpd
 ```
diff --git a/LAMP.md b/LAMP.md
@@ -13,30 +13,28 @@ systemctl enable httpd
 2.MySQL
 ---
 
-For MySQL 8 Community Server (almost 500MB download size and 2.2GB after install), run:
-
-```bash
-rpm -Uvh https://repo.mysql.com/mysql80-community-release-el7-3.noarch.rpm
-sed -i 's/enabled=1/enabled=0/' /etc/yum.repos.d/mysql-community.repo
-yum --enablerepo=mysql80-community install -y mysql-community-server
-systemctl start mysqld
-systemctl enable mysqld
-grep "A temporary password" /var/log/mysqld.log
-```
-
-OR, For MariaDB Server 10.6 (40MB download, 200MB install), run:
+For MariaDB Server 10.6 (40MB download, 200MB install), run:
 
 ```bash
 curl -sL https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | bash -
 yum install -y MariaDB-server
 systemctl start mariadb
 systemctl enable mariadb
-mysql_secure_installation
+mariadb-secure-installation
+systemctl restart mariadb
+#mariadb -u root -p
+#mariadb> show databases;
 ```
 
-Now for configuring password of `root` user and testing:
+OR, For MySQL 8 Community Server (almost 500MB download size and 2.2GB after install), run:
 
 ```bash
+rpm -Uvh https://repo.mysql.com/mysql80-community-release-el7-3.noarch.rpm
+sed -i 's/enabled=1/enabled=0/' /etc/yum.repos.d/mysql-community.repo
+yum --enablerepo=mysql80-community install -y mysql-community-server
+systemctl start mysqld
+systemctl enable mysqld
+grep "A temporary password" /var/log/mysqld.log
 mysql_secure_installation
 systemctl restart mysqld
 #mysql -u root -p

diff --git a/Centos7 LAMP.md → LAMP.md b/Centos7 LAMP.md → LAMP.md
diff --git a/Centos7 LAMP.md b/Centos7 LAMP.md
@@ -0,0 +1,60 @@
+**Note:** For newer versions of PHP and MariaDB, checkout their websites and update the related parts.
+
+1.Apache2
+---
+
+```bash
+yum install -y httpd
+systemctl start httpd
+systemctl enable httpd
+#curl http://127.0.0.1/
+```
+
+2.MySQL
+---
+
+For MySQL 8 Community Server (almost 500MB download size and 2.2GB after install), run:
+
+```bash
+rpm -Uvh https://repo.mysql.com/mysql80-community-release-el7-3.noarch.rpm
+sed -i 's/enabled=1/enabled=0/' /etc/yum.repos.d/mysql-community.repo
+yum --enablerepo=mysql80-community install -y mysql-community-server
+systemctl start mysqld
+systemctl enable mysqld
+grep "A temporary password" /var/log/mysqld.log
+```
+
+OR, For MariaDB Server 10.6 (40MB download, 200MB install), run:
+
+```bash
+curl -sL https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | bash -
+yum install -y MariaDB-server
+systemctl start mariadb
+systemctl enable mariadb
+mysql_secure_installation
+```
+
+Now for configuring password of `root` user and testing:
+
+```bash
+mysql_secure_installation
+systemctl restart mysqld
+#mysql -u root -p
+#mysql> show databases;
+```
+
+3.PHP 7.4
+---
+
+```bash
+yum install -y https://rpms.remirepo.net/enterprise/remi-release-7.rpm
+yum-config-manager --enable remi-php74
+yum install -y php php-cli php-fpm php-mysqlnd php-zip php-devel php-gd php-mcrypt php-mbstring php-curl php-xml php-pear php-bcmath php-json
+#php -v
+#php --modules
+
+echo '<?php phpinfo(); ?>' > /var/www/html/info.php
+systemctl restart httpd
+#curl http://127.0.0.1/info.php
+#rm /var/www/html/info.php
+```
diff --git a/Centos7.md b/Centos7.md
@@ -333,7 +333,7 @@ vim /etc/ssh/config
 service sshd reload
 ```
 
-**Yum:**
+### Yum:
 
 ```bash
 yum list | grep mongo
@@ -344,7 +344,8 @@ yum makecache fast
 package-cleanup --oldkernels --count=1 #for disk cleanup (reboot first to make sure you are using latest downloaded kernel)
 ```
 
-**Copying files:** `source` and/or `destination` could be either a local path or a remote path (in `host:/path` format).
+### Copying files:
+`source` and/or `destination` could be either a local path or a remote path (in `host:/path` format).
 
 ```bash
 scp -p source destination
@@ -354,43 +355,43 @@ rsync -azvhP source destination #for fewer files with larger sizes
 rsync -ah --info=progress2 source destination #for more files with smaller sizes
 ```
 
-**Check Disk Space:**
+### Check Disk Space:
 
 ```bash
 df -h #look for the one mounted at /
 du -sh #./*
 ```
 
-**Check Open Ports by Programs:**
+### Check Open Ports by Programs:
 
 ```bash
 netstat -tulpn
 ```
 
 
-**Get unique IPs from a file:**
+### Get unique IPs from a file:
 
 ```bash
 grep -Po '\d+\.\d+\.\d+\.\d+' /var/log/nginx/access.log | uniq | sort
 grep -Po '\d+\.\d+\.\d+\.\d+' /var/log/nginx/access.log | uniq | wc -l
 ```
 
-**Change hostname:**
+### Change hostname:
 
 ```bash
 #hostnamectl
 hostnamectl set-hostname hostname
 echo 127.0.0.1 hostname >> /etc/hosts
 ```
 
-##### Passwordless SSH:
+### Passwordless SSH:
 
 ```bash
 ssh-keygen # to create id_rsa & id_rsa.pub
 ssh-copy-id SERVER # use password to store your id_rsa.pub into the remote account's authorized_keys
 ```
 
-#### Bash Completions:
+### Bash Completions:
 
 ```bash
 yum install -y bash-completion bash-completion-extras
@@ -407,7 +408,8 @@ echo 'export GIT_PS1_SHOWCOLORHINTS=1 GIT_PS1_SHOWDIRTYSTATE=1 GIT_PS1_SHOWSTASH
 echo "export PROMPT_COMMAND='"'__git_ps1 "\033[1;34m[\033[1;36m\u\033[36m@\h\033[1;34m:\w]\\\$\033[m" "\n> "'"'" >> /etc/bashrc
 ```
 
-**SSH Banner:** you can use some online [ASCII art generator service](https://patorjk.com/software/taag/#p=display&h=1&f=Isometric3&t=name)
+### SSH Banner:
+you can use some online [ASCII art generator service](https://patorjk.com/software/taag/#p=display&h=1&f=Isometric3&t=name)
 
 ```bash
 vim /etc/issue

diff --git a/Centos7.md b/Centos7.md
@@ -312,7 +312,7 @@ source ~/.docker_aliases
 9.Usefull Commands (Bonus)
 ---
 
-##### Adding Users:
+### Adding Users:
 
 When editing `authorized_keys` file for each user, paste that user's public keys from each of his machines in a separate line.
 

diff --git a/Centos7.md b/Centos7.md
@@ -312,7 +312,9 @@ source ~/.docker_aliases
 9.Usefull Commands (Bonus)
 ---
 
-**Add Users:** When editing `authorized_keys` file for each user, past that user's public keys from each of his machines in a separate line.
+##### Adding Users:
+
+When editing `authorized_keys` file for each user, paste that user's public keys from each of his machines in a separate line.
 
 ```bash
 adduser username

diff --git a/Centos7.md b/Centos7.md
@@ -381,21 +381,21 @@ hostnamectl set-hostname hostname
 echo 127.0.0.1 hostname >> /etc/hosts
 ```
 
-**Passwordless SSH:**
+##### Passwordless SSH:
 
 ```bash
 ssh-keygen # to create id_rsa & id_rsa.pub
 ssh-copy-id SERVER # use password to store your id_rsa.pub into the remote account's authorized_keys
 ```
 
-**Bash Completions:**
+#### Bash Completions:
 
 ```bash
 yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-#### Colored Bash Prompt (with Git Prompt):
+### Colored Bash Prompt (with Git Prompt):
 you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -395,7 +395,7 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-##### Colored Bash Prompt (with Git Prompt):
+#### Colored Bash Prompt (with Git Prompt):
 you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -395,7 +395,7 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-###### Colored Bash Prompt (with Git Prompt):
+##### Colored Bash Prompt (with Git Prompt):
 you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -395,7 +395,8 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
+###### Colored Bash Prompt (with Git Prompt):
+you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
 
 ```bash
 curl "https://raw.githubusercontent.com/git/git/$(gitver=$(git --version); echo "${gitver/git version /v}")/contrib/completion/git-prompt.sh" > /etc/.git-prompt.sh

diff --git a/Centos7.md b/Centos7.md
@@ -381,6 +381,13 @@ hostnamectl set-hostname hostname
 echo 127.0.0.1 hostname >> /etc/hosts
 ```
 
+**Passwordless SSH:**
+
+```bash
+ssh-keygen # to create id_rsa & id_rsa.pub
+ssh-copy-id SERVER # use password to store your id_rsa.pub into the remote account's authorized_keys
+```
+
 **Bash Completions:**
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -113,22 +113,25 @@ cat /proc/<nginx-pid>/limits
 ```
 
 
-**For SSL:** create your nginx server in `/etc/nginx/conf.d/DOMAN.conf`, replace DOMAIN and EMAIL in the following with yours, and run the following:
+**For SSL:** first install certbot with it's nginx extentions like below, then run it to issue or install the certificate(s) for your domain(s). Make sure to create your nginx config for those domains in `/etc/nginx/conf.d/DOMAN.conf`, and your `server_name` is similiar to the domain you will issue a certificate for.
 
 ```bash
 yum install -y certbot python2-certbot-nginx
-#certbot certonly --nginx
-#certbot --nginx --non-interactive --agree-tos --redirect -m [email protected] -d www.DOMAIN.com
-certbot certonly --agree-tos --manual --manual-public-ip-logging-ok --preferred-challenges dns-01 -d "*.DOMAIN.com,DOMAIN.com"
-echo "0 0,12 * * * root python -c 'import random; import time; time.sleep(random.random() * 3600)' && certbot renew" | sudo tee -a /etc/crontab > /dev/null
+#certbot certonly --nginx #only issues certificate
+#certbot install --nginx #only installs an already issued certificate
+certbot #issues and installs certificate
 ```
 
-if you run the above before configuring nginx with your `server_name`, you have to run this after doing so:
+Alternatively, replace DOMAIN and EMAIL in the following with yours, and choose to run the one that suits you (wildcard or non-wildcard certificate)
 
 ```bash
-certbot install --nginx
-```
+# for non-wildcard certificates (automatic challange resolving & renewable):
+certbot certonly --nginx --non-interactive --agree-tos --redirect -m [email protected] -d www.DOMAIN.com
+echo "0 0,12 * * * root certbot renew" | sudo tee -a /etc/crontab > /dev/null
 
+# for wildcard certificates (manual issue and renew by resolving dns challange each 3 month):
+certbot certonly --agree-tos --manual --manual-public-ip-logging-ok --preferred-challenges dns-01 -m [email protected] -d "*.DOMAIN.com,DOMAIN.com"
+```
 
 
 3.Node

diff --git a/Centos7.md b/Centos7.md
@@ -362,6 +362,14 @@ du -sh #./*
 netstat -tulpn
 ```
 
+
+**Get unique IPs from a file:**
+
+```bash
+grep -Po '\d+\.\d+\.\d+\.\d+' /var/log/nginx/access.log | uniq | sort
+grep -Po '\d+\.\d+\.\d+\.\d+' /var/log/nginx/access.log | uniq | wc -l
+```
+
 **Change hostname:**
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -104,7 +104,7 @@ For preventing `(24: Too many open files)` errors in nginx, since defaults of ul
 echo "[Service]" >> /etc/systemd/system/nginx.service.d/override.conf
 echo "LimitNOFILE=65536" >> /etc/systemd/system/nginx.service.d/override.conf
 systemctl daemon-reload
-## Add the following to your main nginx.conf
+## Add the following to your main nginx.conf (this number is suitable for 4 workers)
 # worker_rlimit_nofile 16384;
 systemctl restart nginx
 ## Check with the following

diff --git a/Centos7.md b/Centos7.md
@@ -86,15 +86,32 @@ service nginx start
 chkconfig nginx on
 ```
 
-for preventing 403 and permission errors for nginx, if SELinux is in enforcing mode (check with `getenforce`) use the following to allow serving static files
+For preventing 403 and permission errors for nginx, if SELinux is in enforcing mode (check with `getenforce`) use the following to allow serving static files
 
 ```bash
 setsebool -P httpd_can_network_connect on
 setsebool -P httpd_setrlimit on
 chcon -Rt httpd_sys_content_t /var/www # OR /usr/share/nginx/html/
 ```
 
-if the configuration above did not resolve permission issues with nginx filea read or proxying, please read https://www.nginx.com/blog/using-nginx-plus-with-selinux/
+If the configuration above did not resolve permission issues with nginx filea read or proxying, please read https://www.nginx.com/blog/using-nginx-plus-with-selinux/
+
+
+For preventing `(24: Too many open files)` errors in nginx, since defaults of ulimit is low (1024 soft, 4096 hard), you can increase it just for the nginx processes by setting specific configurations in it's systemd service file, like this:
+
+```bash
+# systemctl edit nginx
+echo "[Service]" >> /etc/systemd/system/nginx.service.d/override.conf
+echo "LimitNOFILE=65536" >> /etc/systemd/system/nginx.service.d/override.conf
+systemctl daemon-reload
+## Add the following to your main nginx.conf
+# worker_rlimit_nofile 16384;
+systemctl restart nginx
+## Check with the following
+ps aux | grep nginx
+cat /proc/<nginx-pid>/limits
+```
+
 
 **For SSL:** create your nginx server in `/etc/nginx/conf.d/DOMAN.conf`, replace DOMAIN and EMAIL in the following with yours, and run the following:
 

diff --git a/Centos7.md b/Centos7.md
@@ -339,6 +339,12 @@ df -h #look for the one mounted at /
 du -sh #./*
 ```
 
+**Check Open Ports by Programs:**
+
+```bash
+netstat -tulpn
+```
+
 **Change hostname:**
 
 ```bash

diff --git a/Centos7.md b/Centos7.md
@@ -298,7 +298,7 @@ source ~/.docker_aliases
 adduser username
 passwd -d username
 su username
-mkdir ~/.ssh
+mkdir -p ~/.ssh
 chmod 700 ~/.ssh
 vim ~/.ssh/authorized_keys
 chmod 600 ~/.ssh/authorized_keys

diff --git a/Centos7.md b/Centos7.md
@@ -1,4 +1,4 @@
-**Note:** For newer versions of NodeJS, Nginx and MongoDB, see their sites and update the related parts.
+**Note:** For newer versions of NodeJS, Nginx and MongoDB, checkout their websites and update the related parts.
 
 0.Pre-requisites
 ---

diff --git a/Centos7.md b/Centos7.md
@@ -354,7 +354,7 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: red=31, green=32, yellow=33, blue=34, purple=35, cyan=36)
+**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: 🔴red=31, 🟢green=32, 🟡yellow=33, 🔵blue=34, 🟣purple=35, 💧cyan=36)
 
 ```bash
 curl "https://raw.githubusercontent.com/git/git/$(gitver=$(git --version); echo "${gitver/git version /v}")/contrib/completion/git-prompt.sh" > /etc/.git-prompt.sh

diff --git a/Centos7.md b/Centos7.md
@@ -47,6 +47,7 @@ vim /etc/yum.conf
 OR a DNS proxy in the system level dns:
 
 ```bash
+##yum install -y NetworkManager-tui
 #nmtui
 vim /etc/resolv.conf
 #nameserver 185.51.200.2

diff --git a/Centos7.md b/Centos7.md
@@ -318,7 +318,7 @@ yum downgrade mongodb*
 yum remove mongodb*
 yum clean all
 yum makecache fast
-package-cleanup --oldkernels --count=1 #for disk cleanup
+package-cleanup --oldkernels --count=1 #for disk cleanup (reboot first to make sure you are using latest downloaded kernel)
 ```
 
 **Copying files:** `source` and/or `destination` could be either a local path or a remote path (in `host:/path` format).

diff --git a/Centos7.md b/Centos7.md
@@ -353,7 +353,7 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (remove `1;` for light/bold switch or use `31m` to `36m` for other colors)
+**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (add/remove `1;` for light/bold switch or use other numbers for other colors: red=31, green=32, yellow=33, blue=34, purple=35, cyan=36)
 
 ```bash
 curl "https://raw.githubusercontent.com/git/git/$(gitver=$(git --version); echo "${gitver/git version /v}")/contrib/completion/git-prompt.sh" > /etc/.git-prompt.sh

diff --git a/Centos7.md b/Centos7.md
@@ -324,7 +324,8 @@ package-cleanup --oldkernels --count=1 #for disk cleanup
 **Copying files:** `source` and/or `destination` could be either a local path or a remote path (in `host:/path` format).
 
 ```bash
-scp source destination
+scp -p source destination
+scp -rp source destination
 docker cp source destination #use docker container ID instead of host name
 rsync -azvhP source destination #for fewer files with larger sizes
 rsync -ah --info=progress2 source destination #for more files with smaller sizes

diff --git a/Centos7.md b/Centos7.md
@@ -352,7 +352,7 @@ yum install -y bash-completion bash-completion-extras
 source /etc/profile.d/bash_completion.sh
 ```
 
-**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (remove `1;` for light/bold switch or use `30m` to `37m` for other colors)
+**Colored Bash Prompt (with Git Prompt):** you can change prompt colors by changing `1;34m` and `36m` from the last line (remove `1;` for light/bold switch or use `31m` to `36m` for other colors)
 
 ```bash
 curl "https://raw.githubusercontent.com/git/git/$(gitver=$(git --version); echo "${gitver/git version /v}")/contrib/completion/git-prompt.sh" > /etc/.git-prompt.sh

diff --git a/Centos7.md b/Centos7.md
@@ -365,6 +365,7 @@ echo "export PROMPT_COMMAND='"'__git_ps1 "\033[1;34m[\033[1;36m\u\033[36m@\h\033
 
 ```bash
 vim /etc/issue
+# Put banner content here
 vim /etc/ssh/sshd_config 
 # Banner /etc/issue
 service sshd restart

diff --git a/Centos7.md b/Centos7.md
@@ -361,7 +361,7 @@ echo 'export GIT_PS1_SHOWCOLORHINTS=1 GIT_PS1_SHOWDIRTYSTATE=1 GIT_PS1_SHOWSTASH
 echo "export PROMPT_COMMAND='"'__git_ps1 "\033[1;34m[\033[1;36m\u\033[36m@\h\033[1;34m:\w]\\\$\033[m" "\n> "'"'" >> /etc/bashrc
 ```
 
-**SSH Banner:** you can use some ASCII art generator services like: patorjk.com/software/taag/#p=display&h=1&f=Isometric3&t=name
+**SSH Banner:** you can use some online [ASCII art generator service](https://patorjk.com/software/taag/#p=display&h=1&f=Isometric3&t=name)
 
 ```bash
 vim /etc/issue
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