====== Registering Host Systems ======

Before a system can be used to host Xen instances, Solaris Zones or Linux VServers, VM2 must be informed that is will be used for this purpose, and must verify that needed software and kernel support is installed. The steps to do this are similar for the various virtualization types, but they all start with the registration of the host system itself, documented on the [[Using VM2]] page.

===== Setting up DNS =====

When a virtual system is created by VM2, it will be assigned an IP address and a hostname. To allow this hostname to be used by other systems, it must be added to the DNS so that it can be resolved - otherwise, only the IP can be used to connect.

Fortunately, VM2 can make use of Webmin's BIND DNS Server module to add these DNS records automatically. For this to work, the VM2 master system must be running a name server, and it must have at least one DNS domain configured, as explained below :

  - On the master system, click on the **Webmin** link at the top of the left menu, open the **Servers** category and click on **BIND DNS Server**.
  - If BIND is not installed yet, Webmin will inform you and offer to automatically install it from YUM, APT or Blastwave, if your operating system supports one of those repositories. You should click on the link to install it, which if successful will return you to the BIND module.
  - If you want to create a new DNS domain for virtual systems (recommended), click on the **Create master zone** link above the list of existing domains.
  - In the **Domain name / Network** field, enter the new domain name. If your company's domain is //yourcompany.com// , we recommend a domain like //xen.yourcompany.com// .
  - If the **Email address** field is empty, enter your email address.
  - Click the **Create** button.
  - Click the **Apply Changes** button below the list of domains.

Unless the VM2 master system is already the primary nameserver for the //yourcompany.com// domain, you will need to add an ''NS'' record in that domain for //xen.yourcompany.com// with the hostnmae of the VM2 master system. Using Webmin, the steps to do this are :

  - Login to Webmin on your primary DNS server, and open the **BIND DNS Server** module under the **Servers** category.
  - Click on your company's primary DNS domain, like //yourcompany.com// .
  - Click on the **Address** icon.
  - Unless the VM2 master system is already in your DNS, use the **Add Address Record** form to add it. In the **Name** field you could enter //vm2//, and in the **Address** field the IP of the VM2 system. Then click **Create**.
  - Return to the **Edit Master Zone** page, and click on **Name Server**.
  - In the **Add Name Server Record** form, enter //xen.yourcompany.com// for the **Zone Name**, and the hostname of the VM2 master in the **Name Server** field, such as //vm2.yourcompany.com// . Then click **Create**.
  - Return to the main page of the BIND module, and click the **Apply Changes** button at the bottom of the page.

===== Registering a Xen Host =====

The steps to add a system for Xen hosting are :

  - Make sure the system is configured for Xen as explained on the [[Setting up a Xen Host System]] page.
  - Open the **VM2 Settings** section on the left menu, and click on **Xen Host Systems**.
  - Click on the **Register a system for Xen hosting** link.
  - Select the host system from the **System hosting Xens** menu.
  - In the **Base directory for virtual systems** field, enter an existing directory on the system under which Xen images will be created. This should be on a filesystem with plenty of disk space, and ideally using fast disks and/or RAID.
  - From the **Add Xen systems to DNS domain** menu, select the local DNS domain to which new instances hostnames' should be added.
  - In the textboxes next to **IP address allocation range**, enter the starting and ending IP addresses for a range that will be allocated to new Xen instances. These should be on the same network as the system's primary ethernet interface.
  - Click the **Register** button. If Virtualmin can contact the selected system and verifies that Xen kernel support and commands are available, you will be returned to the list of Xen hosts.

Once at least one system has been registered, you will be able to create Xen instances using VM2.

===== Registering a VServer Host =====

The steps to add a system for Linux VServers hosting are :

  - Make sure the system is configured for VServers as explained on the [[Setting up a VServers Host System]] page.
  - Open the **VM2 Settings** section on the left menu, and click on **VServer Host Systems**.
  - Click on the **Register a system for VServer hosting** link.
  - Select the host system from the **System hosting VServers** menu.
  - In the **Base directory for virtual systems** field, enter an existing directory on the system under which VServer filesystems will be created. This should be on a filesystem with plenty of disk space, and ideally using fast disks and/or RAID.
  - From the **Add VServer systems to DNS domain** menu, select the local DNS domain to which new instances hostnames' should be added.
  - In the textboxes next to **IP address allocation range**, enter the starting and ending IP addresses for a range that will be allocated to new VServer instances. These should be on the same network as the system's primary ethernet interface.
  - If you will not be using VM2 images to create VServers, the **Distribution to install on VServers** field can be used to enter a distribution code like //fc6// or //edgy// or //sarge// .
  - Because VServer systems created without images are often missing important packages by default, the **Packages to install on VServers** section can be used to select some that you may want installed. 
  - Click the **Register** button. If Virtualmin can contact the selected system and verifies that VServers kernel support and commands are available, you will be returned to the list of VServers hosts.

Once at least one system has been registered, you will be able to create VServers instances using VM2.

===== Registering a Solars Zones Host =====

The steps to add a system for Zones hosting are :

  - Open the **VM2 Settings** section on the left menu, and click on **Solaris Zones Host Systems**.
  - Click on the **Register a system for Solaris Zones hosting** link.
  - Select the host system from the **System hosting zones** menu. Naturally, this must run Solaris.
  - In the **Base directory for zones** field, enter an existing directory on the system under which zones filesystems will be created. This should be on a filesystem with plenty of disk space, and ideally using fast disks and/or RAID.
  - From the **Add systems in zones to DNS domain** menu, select the local DNS domain to which new instances hostnames' should be added.
  - In the textboxes next to **IP address allocation range**, enter the starting and ending IP addresses for a range that will be allocated to new zones. These should be on the same network as the system's primary ethernet interface.
  - Click the **Register** button. If Virtualmin can contact the selected system and verifies that they run Solaris, you will be returned to the list of zones hosts.

Once at least one system has been registered, you will be able to create Solaris Zones using VM2.