How do snapshots work in VMware Workstation?
By Steven Warren | November 20, 2008, 10:58 AM PST
Snapshots in VMware Workstation is a great feature. It allows you to have one virtual machine (vm) with dozens of different scenarios. In this post, I take a deeper look at snapshots in VMware Workstation.
One of the great features of VMware Workstation is the ability to take snapshots of your virtual machines at any point in time. Previous to VMware Workstation, you were allowed to take only one snapshot per virtual machine. VMware Workstation offers you the ability to take multiple snapshots and manage them with the Snapshot Manager. This adds a whole new layer to your testing and installations. You can create snapshots with specific service packs installed. For example, you might have two snapshots for your Windows XP virtual machines — one with a baseline for service pack 1 and one with a baseline for service pack 2. Furthermore, you might have test plans for training that have 10 snapshots,with each snapshot representing part of the lesson. The functionality this presents can be used in a vast number of ways, depending on your needs.
In addition to taking multiple snapshots, you also have the ability to suspend and resume the state of your virtual machine with VMware Workstation. This is very helpful when you want to save the current state of your virtual machine and resume at a later date to continue your installation and/or testing. If you have worked before with any release of VMware Workstation, you will notice the increase in speed of the suspend/resume feature. You can suspend or resume and take snapshots of virtual machines in seconds.
Definition of a snapshot
When you decide to take a snapshot or “picture” of your virtual machine, the memory, settings, and virtual disk are captured and frozen in time at that specific moment. At any time, you can revert back to that original configuration, losing all changes you made since that snapshot was taken. This is very helpful when you want to test specific scenarios over and over again without having to reinstall the operating system. Currently, when you take a snapshot, the snapshot is saved in the directory where the virtual machine was created using the wizard. Now that you have the ability to take multiple snapshots, you can save snapshots in a linear or tree-like structure. Let’s go over this in more detail.
Using snapshots as restore points
Let’s suppose you are a classroom instructor teaching a Windows 2003 Server course. Each chapter lesson plan contains a specific configuration that you want your students to have in order for the lesson to be effective. You have each student running VMware Workstation in the classroom. By creating snapshots in a linear fashion, you can have each lesson preloaded with the correct configuration. This is an extremely effective way of saving time and effort when you create classroom scenarios. Figure A shows visually what this might look like in VMware Workstation. The lesson plan starts off with a Base Installation of Windows ME.
Using snapshots in a tree structure
Now, let’s suppose you work in the Quality Assurance (QA) department for swTechworks Company, and your primary job is to test its Web application. With VMware Workstation, you can create a treelike testing plan with snapshots, as shown in Figure B.
As you can see the scenarios are endless with what you can do with snapshots.