Practical Cloud Knowledge: Install, Configure, and Manage - Deploying and Managing a Cloud Infrastructure - page 192

EXERCISE 7.6 (continued)
2. Clones can be created in different ways, but with all methods, you need to shut down
the virtual machine before proceeding.
The reason for this requirement is that the virtual machine files cannot be modified
during the cloning process.
Another reason has to do with process and file ownership in operating system file
systems such as those used by Windows and Linux, which do not allow multiple pro-
cesses to modify the same files at the same time. So if a virtual machine is using its
files and resources, the hypervisor cannot work on those files to create the clone.
There are specific configurations for which the requirement of shutting down virtual
machines is no longer enforced, such as when you are using VMware Virtual Machine
File System while at the same time using VMware ESXi as a bare metal hypervisor .
In VMware Workstation and ESXi, the most straightforward method is choosing the
Manage option from the VM menu and then selecting the Clone option in order to
start the wizard.
In the first step, the wizard asks what the source of the clone will be. The source can
be a snapshot of a virtual machine state if there are any, or you can base it on the
current state, which will create a snapshot.
3. Select the source.
4. Select either a full or linked clone, the differences of which we discussed previously.
But just to reiterate, when selecting a full clone, you have to make sure that there is
enough disk space because the full clone will take up approximately the same disk
space used by the source virtual machine on the host computer. This includes all of
the files in the virtual disks, so if the source virtual machine takes up 50 gigabytes of
space on the host machine, you will need at least that much extra space on the host
as well.
5. Verify that there is ample disk space, and then the cloning process can begin.
6. Name the clone and decide where it should be stored on the host computer.
After completion, the clone with the assigned name should appear on the console and
in the library as an independent virtual machine because that is what it actually is.
The other way of creating clones is through the snapshot manager of your hypervisor.
Simply select the snapshot you want and the click Clone.