If you’re planning to take the Security+ exam, you should have a basic understanding of virtual systems. Virtualization allows you to host one or more virtual systems on a single virtual server.
See if you can you answer this question?
Q. You are preparing to deploy a new application on a virtual server. The virtual server hosts another server application that employees routinely access. Which of the following is the BEST method to use when deploying the new application?
A. Take a snapshot of the VM before deploying the new application.
B. Take a snapshot of the VM after deploying the new application.
C. Apply blacklisting techniques on the server for the new applications.
D. Back up the server after installing the new application.
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Virtualization is a technology that has been gaining a lot of popularity in recent years. It allows you to host one or more virtual systems, or virtual machines (VMs), on a single physical system. With today’s technologies, you can actually host an entire virtual network within a single physical system and organizations are increasingly using virtualization to reduce costs.
Snapshots
Snapshots provide you with a copy of the VM at a moment in time, which you can use as a backup. If the VM develops a problem, you can revert the image to the state it was in when you took the snapshot. You are still able to use the VM just as you normally would. However, after taking a snapshot, the hypervisor keeps a record of all changes to the VM.
Administrators commonly take snapshots of systems prior to performing any risky operation. Risky operations include applying patches or updates, and installing new applications. Ideally, these operations do not cause any problems, but occasionally they do. By creating snapshots before these operations, administrators can easily revert the system to the previous state.
Sandboxing and Security Control Testing
A sandbox is an isolated area and is often used for testing programs. When using VMs, you can create them so that they are isolated in a sandbox environment. Sandboxing prevents the VMs from interacting with any other VMs, the physical host, or devices on the network. The term comes from a sandbox in a playground. Children can play in the sandbox where they are relatively safe (and parents can easily keep their eyes on them). Similarly, application developers can play in a virtual sandbox knowing that any changes they make will not affect anything outside the sandbox.
Administrators and security professionals also use sandboxing to test various security controls before deploying them to a live production network. Virtualization provides a high level of flexibility when testing security controls because the environments are easy to re-create. For example, they can test the effectiveness of antivirus software to detect malware released within a sandbox. If the antivirus software doesn’t detect the malware and the malware causes problems, it is easy to revert the system to a previous state using a snapshot. Also, the isolation within the sandbox prevents the malware from spreading.
Similarly, virtualized sandboxes are useful for testing patches. For example, software vendors typically develop software updates and patches, but they need to test them in various environments before releasing them. They could create VMs for multiple operating systems. When they’re ready to test, they turn on one of the VMs, take a snapshot, and then apply and test the patch. If the patch causes a problem, they can easily revert the VM.
Q. You are preparing to deploy a new application on a virtual server. The virtual server hosts another server application that employees routinely access. Which of the following is the BEST method to use when deploying the new application?
A. Take a snapshot of the VM before deploying the new application.
B. Take a snapshot of the VM after deploying the new application.
C. Apply blacklisting techniques on the server for the new applications.
D. Back up the server after installing the new application.
Answer is A. Taking a snapshot of the virtual machine (VM) before deploying it ensures that the VM can be reverted to the original configuration if the new application causes problems.
Taking a snapshot after the installation doesn’t allow you to revert the image.
Blacklisting prevents an application from running, so it isn’t appropriate for a new application deployed on a server.
Backing up the server might be appropriate before installing the new application but not after.
You may also like to view the blog post about Container Virtualization.
