Sysadmin blog More Mins: Virtualmin is an open core extension to Webmin. It allows a systems administrator to manage all the elements to provide shared hosting to multiple customers from one Linux server. Unlike Webmin, in which you configure all of the elements on a per-application basis, Virtualmin approaches configuration domain by domain, abstracting configuration of the applications away from the administrator.
When you set up a domain on Virtualmin, you can configure applications to provide a fully featured set of web services from a single interface. Virtualmin will set up Linux users, ftp, email, DNS, web space and database access. Virtualmin uses Apache to host web sites and BIND for DNS. Email support is from Postfix, dovecot Cyrus and saslauthd. Databases services are provided by MySQL.
Users in Virtualmin fall into several categories. Resellers have the right to create new virtual servers. Virtual Server Owners (VSOs) have the rights to manage individual virtual servers while Mail/FTP users belong to a given virtual server. They are exactly what they sound like.
This concept of virtual servers is different to x86 virtualisation, though it shares some of the same terminology. For Virtualmin, the reference is to Apache’s virtual servers: a slice of a shared space on a single server. All virtual servers share the same copy of Apache, BIND, MySQL, Postfix etc. They experience resource contention in the traditional way, and are only sandboxed from one another as far as kernel and operating system security allow.
Deep breath: a virtual server can host multiple domains, but hosting a subdomain requires a separate virtual server. Though technically a separate virtual server, subdomains are treated as “Sub-Servers” of the Primary Virtual Server by Virtualmin, meaning that a Virtual Server Owner has the right to administer any Sub-Servers that may descend from the Virtual Server they are responsible for.
Virtual Server Owners control their provisioned virtual environment, including the ability to manage SSL certificates. As of version 3.64, Virtualmin supports hosting multiple SSL websites from a single address. While Virtualmin cannot overcome the inherent one-certificate-per-IP limitation of SSL, wildcard certificates, multi-domain certificates and unified communications certificates mean that a Virtual Server Owner can install certificates that will respond to all of his Virtual Servers and Sub Servers from a single IP.
Virtual Server Owners can generate Certificate Signing Requests and apply certificates while a registrar plugin allows for the registration of domains without leaving the Virtualmin interface. Managing Mail/FTP users allows a Virtual Server owner to configure user’s email, access to FTP as well as access to Usermin. Virtual Server Owners can also configure cron jobs, URL redirects, email forwarding and manage backups. To monitor it all, Virtualmin provides a good statistics and logging interface, making use of AWStats and Webalizer.
Rounding it all out is Virtualmin’s integrated support for deploying dozens of popular blogs, content management systems, wikis, development frameworks and many other scripted services such as SVN, Git or SugarCRM. A few mouse clicks is enough to spawn an instance of any of the supported scripts. Virtualmin’s integration with Webmin and Usermin provides a unified and easy-to-use interface for managing all aspects of web provisioning, whether you are selling services to customers or managing your internal web infrastructure. As an open core project, not all features are available in the free GPL version of the software. For those stumping up for the paid version, a 10 virtual server licence costs $139. An unlimited lifetime license costs $999 - and there are, of course, many points between. ®