In a previous post we discussed about procedure for the export of a virtual machine as an appliance. This post will explain the procedure for importing those appliances back to our system.
We can use those appliances as a templates for our new virtual machines and import them multiple times. With this technique we can build whole network very fast. However, every virtual machine will occupied same amount of the disk space. If we’re short with the disk space, we can consider using linked clones of existing virtual machine.
Moreover, we can build a whole solutions in our lab and then just gave completely configured virtual machine to the user. After that, user just need to follow simple procedure to import that template to his system and have new virtual machine ready.
In many cases transferring a virtual machine using an appliance is faster way to deploy whole solution. Regardless how fast you can install the operating system or an application itself, you will always need some extra time to configure whole solution. With the appliance we need to setup an environment just once and then we can deploy it on every platform that supporting our virtual environment.
Depending on size of the virtual machine, our template can be smaller or larger. We can transfer it on a USB flash drive or on an external HDD. Our customers can even download it from the FTP server or some file sharing platform on the Web.
In our example, we will use an appliance for the Mikrotik RouterOS device. It’s small and we can transfer it on the USB pen drive. We’ll plug the USB flash drive in the USB port and wait for our computer to detect it.
Now we will open the Oracle VM VirtualBox Manager and choose File > Import appliance. The keyboard shortcut is Ctrl + I.
New windows will appear. We can now search for appliance file. Just click on the icon of the folder with the green arrow pointing upward.
This will open a standard dialog for the file opening. We will navigate to our disk and locate the appliance file. This is file with .ova extension. It has red box as icon, opposite to the standard virtual machine configuration file icon which is blue.
When we select the desired file, this dialog will be close and we will return to the previous window. However, we have the complete path to the file.
In the next window we can change some parameters of this virtual machine. This window can be smaller then the list and some parts are not visible. We can enlarge this window and we will see whole list of the parameters.
As we can see, we are free to change almost everything, starting from the virtual machine name. It’s not wise to change predefined parameters without very good reason. We can change a name of the virtual machine or we can assign more RAM to it. However, we should always consider that someone who created this appliance already tuned it for optimal resource usage.
In this example I will change the name of the virtual machine and decrease amount of memory to the minimal supported value. Therefore, this operation is safe in this case. Again, be careful when you changing those parameters.
Please, pay attention that I checked box Reinitialize the MAC addresses of all network cards. We can import same template multiple time. We must give new name for every new virtual machine and assign different MAC address. We can’t have two hosts (physical or virtual machines), inside same Layer 2 network segment, that have identical MAC address assigned to the network card.
We will click now on the button [ Import ] and wait for the importing process to finish. That can take some time, depending on the size of the virtual machine. After import, a new machine will appear in the list.
As we can see, out newly deployed virtual machine have new name and only 32 MB of the RAM. As our virtual machines are under Mikrotik RouterOS operating system, new virtual machine will have different serial number. Therefore, we will need separate license in case that we need to run production router. Same applies to the Windows based virtual machines.
We can now start both machines and working on them independently. First, we will check if everything is correct with new virtual machine. Then we can proceed with our project.
For the end, one small hint. As you can see, I have the virtual machine named RouterOS v6 UPS test. I tested an UPS support on the Mikrotik platform and you can expect the post about this feature soon.