OS installation

OS installation procedure consists of the following steps: 

1. The system generates the values for parameters and macros for the OS template. Learn more in OS template macros.
2. Installs the operating system on the server.
3. Copies and starts the recipes on the server via SSH. 

OS installation steps for Linux, Windows and  FreeBSD are described below:

Linux

The OS installation process includes the following steps:

1. VMmanager configures a virtual machine to start the installation script. Every template has a number of reboots that can be made before the system will consider the operating system to be installed.
2. Starts the virtual machine.
3. The installation script receives values of OS template macros from VMmanager.
4. The system adds the counter of remaining reboots before the OS installation completes, into the vm table of the database.
5. The virtual machine is suspended so that it won't stop during reboot.
6. The script installs an operating system.
7. The script reboots and suspends the virtual machine.
8. vmwatch-node on the cluster nodes retrieves the information that the virtual machine was suspended from libvirtd and sends the corresponding notification to vmwatch-master.
9. vmwatch-master processes the information and calls the API function vm.event. The function parameters contains the cluster node ID, the VM name, type and subtype of the event..
10. VMmanager executes the function vm.event and analyses the received data. If the OS installation mark is specified in the VM database, VMmanager performs the following operations:
    
    1. Decreases the reboot counter.
    2. If the reboot counter is 0: it will change the configuration of the virtual machine so that the next reboot will be performed from the main disk; deletes the indication of OS installation for the virtual machine.
    3. Starts the virtual machine.
    4. If the reboot counter is not 0: the system will repeat the steps starting from Step 4.

Windows

The OS installation process includes the following steps:

1. Deploys the ready image of the installed operating system. The script C:\vmmgr\firstrun.cmd will run during the auto-start.
2. The system starts the virtual machine.
3. Mounts the 1 MB virtual disk that contains the configuration script.
4. Starts the firstrun script and using the dd utility reads the configuration script from the mounted virtual disk.
5. The configuration script starts and configured the virtual machine.
6. Reboots the virtual machine.

FreeBSD

The OS installation process includes the following steps:

1. Deploys the modified image of the installation disk bootonly.iso.
2. Starts the virtual machine.
3. Adds the first start script into the auto-boot file /etc/rc.local.
4. Mounts the 1 MB virtual disk that contains the configuration shell-script.
5. The first start sctipt reads the configuration of the mounted virtual disk and saves it into /tmp/install.sh.
6. The configuration script starts and configured the virtual machine.
7. Reboots the virtual machine.