Shell

Step 1. Connect to the server as root or execute commands as sudo

#sudo su

Step 2. remove all log files

rm -rf /var/log/apache2/*

rm -rf /var/log/virtualmin/*

....

Step 1.

Check apache error log (use tail to show in real time)

# tail -f /var/log/apache2/error.log

Step 2 : 

Check MySQL database connection using mysql -uusername -ppassword

To handle drupal with drust, First of all, you must install drush, and execute drush command from your drupal instalation folder.

Enable a Features

drush en feature_name

Revert a feature

drush fr freture_name

Revert all features

drush fra -y

#OR Also

drush fr-all

Install in Windows.

1. Install npm (Node.js) : https://www.npmjs.com/package/npm 
2. Install grunt-cli (npm install -g grunt-cli)

Zip and Unzip Files on Linux (With zip and unzip)

Ziping files/directories

zip file *

zip -r file *

Unziping files/directories

unzip  file.zip

extract a file

unzip file.zip  file.doc

To disable phpmyadmin module, run followin command ad root or sudo:

sudo a2disconf phpmyadmin

sudo service apache2 reload

OR

a2disconf phpmyadmin

service apache2 reload

Run : which composer

Result exemple : /usr/local/bin/composer

The solution is:

ssh-keygen -R <host>

Example:

ssh-keygen -R 127.0.0.1

ssh-keygen -R domainname.com

Inlinux debian / ubuntu / mint ...

1. Install imagemagick tools (if not installed)

# sudo apt-get install imagemagick

2. Process images like : (here resize images to 50%)

$ for i in $( ls *.jpg); do convert -resize 50% $i re_$i; done