If you’re planning on taking the Security+ exam, you should have a basic understanding of snapshots with virtualization.
For example, 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?
Answer and explanation at end of this post.
Understanding Virtualization
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.
When discussing VMs and studying for the CompTIA Security+ exam, you should understand the following terms:
- Hypervisor. The software that creates, runs, and manages the VMs is the hypervisor. Several virtualization technologies currently exist, including VMware, Microsoft Hyper-V, Windows Virtual PC (VPC), and Oracle VM VirtualBox. All of these have their own hypervisor software.
- Host. The physical server hosting the VMs is the host. It requires more resources than a typical system, such as multiple processors, massive amounts of RAM, fast and abundant hard drive space, and one or more fast network cards. Although these additional resources increase the cost of the host, it is still less expensive than paying for multiple physical systems. It also requires less electricity, less cooling, and less physical space.
- Guest. Operating systems running on the host system are guests or guest machines. Most hypervisors support several different operating systems, including various Microsoft operating systems and various Linux distributions. Additionally, most hypervisors support both 32-bit and 64-bit operating systems.
- Patch compatibility. It’s important to keep VMs patched and up to date. Patches applied to physical systems are compatible with virtual systems.
- Host availability/elasticity. Elasticity refers to the ability to resize computing capacity based on the load. For example, imagine one VM has increased traffic. You can increase the amount of processing power and memory used by this server relatively easily. This allows you to ensure it remains available even with the increased demand.
The 601 Version of the Study Guide
The CompTIA Security+: Get Certified Get Ahead: SY0-601 Study GuideEach of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.
Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
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.
Remember this
Virtualization allows multiple virtual servers to operate on a single physical server. It provides increased availability with lower operating costs. Additionally, virtualization provides a high level of flexibility when testing security controls, updates, and patches because they can easily be reverted using snapshots.
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.
A is correct. 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.
