Snapshot and cloning summary for VMware

Introduction to Multi-snapshot features:

The meaning of a snapshot: a mirror with a read-only attribute for a particular file system at a specific time. You can use the snapshot feature when you need to return to a system state repeatedly and do not want to create more than one virtual machine. In fact, snapshots are notVMware Workstation 5of new features. Back inVMware Workstation 4time, the snapshot feature has been supported. ButVMware Workstation 4only one snapshot can be generated, i.e.,VMware Workstation 4The virtual machines created have only two states: the current state and the snapshot state. It's not flexible enough to use. Compared with theVMware Workstation 5and other upgraded versions of the multi-snapshot feature are really powerful. The new multi-snapshot feature allows more than two snapshots to be created for a single virtual machine, which means that we can make multiple snapshots of the system environment at different times, with unlimited round trips to and from any snapshot. At the same time the snapshot manager, the image provides aVMwarethe relationship between multiple snapshot mirrors. The tree-like structure allows us to easily browse and use the generated snapshots. So what exactly does the new snapshot feature bring us? In fact, multiple snapshots do not simply save multiple states of a virtual machine, and by creating multiple snapshots, you can save multiple states for different jobs and do not affect each other. For example, when we do experiments on the virtual machine or test, inevitably encountered some unfamiliar places, at this time to take a snapshot, back up the current system state, once the operation is wrong, you can quickly revert to the state before the error, complete the experiment, and ultimately avoid a step to restart the entire experiment or test results.

To create a snapshot, proceed as follows:

1.start a virtual machine, click VM in the menu, expand Snapshot(snapshot), click take Snapshot ... (creates a snapshot of the current state)

2.in the Create Snapshot window, fill in the name and comment of the snapshot, and clickOK.

What is cloning?  

Said snapshot, then, what is the clone of the virtual machine? In VMware software, cloning and snapshot functionality are similar, but different, and slightly less noticeable are confusing. A clone of a virtual machine is a copy of the entire state of the original virtual machine, or a mirror. The cloning process does not affect the original virtual machine, the cloning operation once completed, the cloned virtual machine can be isolated from the original virtual machine, and in the cloned virtual machine and the original virtual machine operations are relatively independent, do not affect each other. During cloning,VMware generates a different MAC address and UUIDfrom the original virtual machine, This allows the cloned virtual machine to appear on the same network as the original virtual machine without any conflicts. VMware supports two types of clones: Full clone linked clone

A full clone is a completely separate copy of the original virtual machine, and it does not share any resources with the original virtual machine. Can be used independently from the original virtual machine.

A linked clone needs to share the same Vdisk file as the original virtual machine and cannot run independently from the original virtual machine. However, the use of shared disk files greatly reduces the time to create a cloned virtual machine, while also saving valuable physical disk space. Linked clones make it easy to create a standalone virtual machine for different tasks.

Create a cloned virtual machine :

1.open a virtual machine and click the "cloneThis virtual machine" button.

Note: Cloning a virtual machine can only be done in a state where the virtual machine is not started.

2. On the Clone Virtual Machine Creation Wizard page, click Next.

3. Choose to create a clone from the current state or a snapshot.

As you can see, the cloning process can be manipulated either by the current state of the virtual machine or by mirroring the mirror or snapshot of an existing clone.

4. On theclone Type Selection page, you can choose the type of clone virtual machine you created,linkedclone(Contact clone), orfull clone. A connected clone points to the original virtual machine, consumes little disk space, but must rely on the original virtual machine and not be able to run independently from the original virtual machine. A complete

Clone provides a copy of the current state of the original virtual machine, which can run independently, but consumes a lot of disk space.

Here we select Createa linked clone(create linked clone) and click Next.

5. Fill in the name of the cloned virtual machine on the new virtual machine Name page and determine where the new virtual machine is installed.

6. Click Finish to complete the creation of the new clone. In the same way, we can create clones of multiple virtual machines.

the difference between a snapshot and a clone :

Speaking so much, in order to make people more clearly understand the difference between snapshot and cloning, we might as well make a table to summarize.

Snapshot Cloning

creation Time     Not Limited virtual machine can only be

Create Quantity     Not Limited Not Limited

Disk space consumption Determined by the number of created, smaller Determined by the number of creation, the full clone is larger

Use save a virtual machine at a moment state distributing the created virtual machines

is independent You cannot run a linked clone independently from the original virtual machine: partially detached from the full clone: completely detached from

can I use both     can't cloned virtual machines can be used concurrently with the original virtual machine

whether the network uses     can't generates a different MAC address and UUIDfrom the original virtual machine, which can be used simultaneously in the network

Management of Mirroring:

Whether it is a snapshot or a clone, a mirror is generated for a state of the virtual machine, and the difference is that the image is present as part of the virtual machine or as a separate part. In short, we can create multiple mirrors from VMware to save the virtual machine's different time states. How do we manage so many mirrors? Let's take a look at our results through the snapshot manager.

VMware provides a snapshot manager for managing images and snapshots. In the snapshot manager, the snapshot tree image shows the hierarchy of the current multiple snapshots. Click Manage any of these images to give the image a name, write the necessary comments, delete the snapshot, and create a new clone based on the selected snapshot. With the snapshot manager, the management of snapshots is easy.

Snapshot and cloning summary for VMware