Please find below the answers to commonly asked questions we receive about virtual hosting on our Virtual Servers. We hope this helps you better understand virtual hosting, its benefits, and its limitations.

Q1: Is virtual hosting supported on all of the Virtual Server systems?

Yes. Virtual hosting will work on both the Basic Virtual Server (Server A) as well as the Full Featured Server Virtual Servers (Servers B and C). Virtual hosting will not work as well on a Server A because you won't be able to use "vadduser" to add an FTP account for your virtual host. Thus you (as the Administrator) will have to upload all of the files for your clients. You will still be able to allow for a cgi-bin and email aliasing for the virtual hosts on Server A, however. We *recommend* that you use virtual hosting only on Full Featured Virtual Servers (B and C). There is no technical limitation to doing virtual hosting on a Server A, only inconvenience.

Q2: To use the virtual host for www.myclient.com, am I correct to assume that my client needs to register with InterNIC? If that is the case, will Blue Reef provide the registration service?

Yes. All domains must be with registered with InterNIC (or with the appropriate registrar for their country code). InterNIC will charge a $70 registration fee that is good for the first two years. Blue Reef charges you a $35/domain processing fee. If you need a new domain name for a Virtual Server you administer, then simply use our online Order Web Site.

Q3: If the virtual host package cannot offer Telnet access (a shell account), how can our virtual hosted clients upload their data to the server?

You will want to offer FTP access and POP accounts for your Virtual Hosts by using the vadduser command at the Telnet prompt. When prompted for the "home" directory for the FTP account, you will want to specify the same value that you use for the DocumentRoot definition. This will allow your subhosted client to publish web content to their virtual host. Multiple FTP and POP accounts only available on the Full Featured Virtual Server (Server B) and Enhanced Full Featured Virtual Server (Server C). Multiple FTP/POP/IMAP accounts are not supported on the Server A.

Q4: Is there any way to restrict disk usage for the virtual hosting subdirectories?

Yes. When you grant FTP privileges to your clients using the vadduser command, give them FTP rights to their virtual host directory and an FTP quota. They will be prevented them from uploading files that would cause them to exceed the quota you gave them.

Q5: In a nutshell, how is virtual subhosting possible in the Virtual Server environment?

Your virtual server includes your own individual web server software, including a complete set of web server configuration files so configuring multiple virtual hosts using your configuration files is easy. See our Virtual Subhosting section for more details.

Q6: I assume that non "HTTP_HOST" browsers can still connect successfully to the main server? If not, what errors do they get?

One potential problem area is going to be from the older AOL browsers. If the browser does not support the HTTP_HOST variable (i.e. it is not HTTP/1.1 compliant), the client will simply get the main home page of the Virtual Server. For example, if the primary domain name of your Virtual Server is "my-virtual-server.com" and the domain, "a-virtual-host.com", is virtual subhosted on the Server. Any non-HTTP/1.1 requests for "a-virtual-host.com" will receive the root server content, or in this example, the content for "my-virtual-server.com".

Note: This case is extremely rare. At least 99% of internet users uses HTTP/1.1 compliant browsers.

One way around this is to subhost all of the domains associated with the Virtual Server. Then create a "directory", or simply an index.html file in the main htdocs area. Then, when HTTP/1.0 clients request a virtually hosted domain name, they will see a directory of domain names and can then jump to the appropriate content. That way the people with older browsers will still be able to access the pages.

Q7: If I have a customer that wants a virtual host but doesn't want its own domain name, can I create a virtual host like "user.myvirtualserver.com"?

Yes. It is possible to add canonical names to your domain name and have them configured to point to subdirectories of your own server. For example, if your company is reselling Blue Reef Virtual Servers and wants to appear as though it to has all kinds of web servers, you could configure "http://support.myvirtualserver.com", "http://search.myvirtualserver.com", and "http://sales.myvirtualserver.com" as subhosted canonical names on your Virtual Server. Each canonical name would point to a different directory with different content. If you need a new canonical name for a Virtual Server you administer, then simply write to us at orders@bluereef.net.

To configure "http://support.myvirtualserver.com" to point to a subdirectory, you would add something like the following to your httpd.conf file:

# point support.myvirtualserver.com
# to subdirectory support
<virtual host support.myvirtualserver.com>
ServerName support.myvirtualserver.com
ServerAdmin support@myvirtualserver.com
DocumentRoot /usr/local/etc/httpd/htdocs/support
</virtual host>

After you provide a small site and proof of concept, you can then provide additional consulting services (web design, ecommerce, etc) and make a greater profit. Virtual hosting allows you to get your foot in the door of many small businesses.

Q8: If a virtual host has its own CGI-BIN, are the CGI scripts allowed to play with the directory system of the Virtual Server or do they operate safely with their own "sandbox"?

Scripts executed in a virtually hosted cgi-bin will run as your username with all your rights and permissions. Therefore, you will have to be careful about security issues. For example, if your subhosted client uploads a CGI script that executes a command that recursively deletes all files on your Virtual Server there is nothing in place to stop them from doing such an action.

In most cases however, it is likely that not only are you providing your clients with hosting service, but you are also designing their web content and writing their CGI scripts as well. So this may be a non-issue. If you are allowing your subhosted clients to upload their own CGI scripts, then you will want to take some extra precautions. Please see our document, Virtual Subhosting and Security Issues for more information.

Q9: Are there limits to the amount of virtual hosts I can place on a single Virtual Server System?

Theoretically, no, but you will want to use some good sense. In order to maintain the highest performance standards possible, you should carefully consider exactly how many subhosts you place on a single Virtual Server. Please consider the following recommendations:

Server A:   around  5 subhosts
Server B:   around 25 subhosts
Server C:   around 60 subhosts

The exact amount of subhosts that your Virtual Server can handle depends upon the traffic each subhost generates. If the subhosts have relatively light traffic, then these recommendations would be slightly low. If the subhosts generate heavier traffic, then the recommendations above may be a little high. In many cases the traffic generated by a single site will consume the Virtual Server resources to the extent that subhosting other sites will not be possible.