Prerequisites:
– Create a new fcgi driven user in Linux system(in this case usrblog)
useradd -s /bin/bash -d /www/clients/mywpsite.com/htdocs/ usrblog
passwd usrblog

– Install a Virtual host which uses suexec and fcgi in Apache/NginX
– Create a new database in MySQL (we will call it myblog)
– Create a new mysql user and assign the database(myblog) access and control to this user.
– Create web space(DocumentRoot) in system which will be owned by the system user usrblog

Continuing the installation using the wp_cli script
– Install the script as per: http://wp-cli.org/
curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar
chmod +x wp-cli.phar
sudo mv wp-cli.phar /usr/local/bin/wp

Switch user to usrblog
su - usrblog
wp core download
wp core config --dbhost=dbhost --dbname=dbname --dbuser=username --dbpass=password
chmod 644 wp-config.php
wp core multisite-install --subdomains --url=yourwebsite.com --title="Your Blog Title" --admin_name=wordpress_admin --admin_password=4Long&Strong1 --admin_email=you@example.com

The rest is done via the web administration site of the wordpress:
– http://mysite.com/wp-admin
– Select: my site ==> Network Admin ==> Dashboard ==> Settings ==> Network Setup
Copy the rewrite and paste the presented rewrite rules into an new .htaccess file in the htdocs of the site.