By Alison / Last Updated September 5, 2022

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Virtual Machine Backup Overview & Necessity

A virtual machine (VM) is a virtual environment based on computer architectures and provide functionality of a physical computer. It allow users to run an operating system in a single application window, providing a secure sandbox to test programs or access virus-infected data.

Virtual machines are run on hypervisor, and a hypervisor allows one host computer to support multiple guest VMs by virtually sharing its resources. There are mainly 2 types of hypervisors:

Type 1 hypervisor: also known as bare-metal hypervisor, runs directly on the computing hardware. VMware ESXi and Microsoft Hyper-V are the most commonly used type 1 hypervisor.
Type 2 hypervisor: also known as hosted hypervisor, runs on top of the operating system of the host machine. VMware Workstation is the most commonly used type 2 hypervisor.

Whichever host you are running VMs on, there may be data loss caused by virtual server or physical device failures, abnormal shutdown, or other mis-operations. Therefore, it is essential to create virtual machine backup regularly.

By creating VM backups, you can effectively ensure that important data can be restored in time if it is lost. Implementing a good VM backup strategy can enable faster disaster recovery, and keep business continuity.

Best Practices to Backup Virtual Machine for Free

Virtual Machine Backup vs Snapshot, Are They the Same?

A common myth about VM backup is how it differs from the VM snapshot and whether they can replace each other? To answer this, let's take a closer look of fhe 2 concepts:

VM snapshots: Snapshots (or checkpoints for Hyper-V) record the state of a VM at a point in time, including all data, memory, devices on the network, network interfaces, and power state. It can roll back the VM to that point in time when problem occurs. However, it relies on pre-existing physical or virtual machine files to restore data.

VM Backups: Backups are complete copies of virtual machines, but independent of the VM. They can be securely stored in the cloud, in a separate location, or offsite. They allow you to recreate VMs without relying on source VMs.

VM Snapshot vs Backup

VM snapshot vs VM backup: Simply put, a snapshot can be seen as a means of backup in a broad sense, but it is not a complete replacement for a backup. To better distinguish them, here I list 3 main differences:

  VM snapshot VM backup
Data security Snapshots depend on the parent disk, and record incremental changes from a point in time. If a VM's parent disk is deleted, you cannot restore it from snapshot VM backups are independent and not affected by this
Backup Speed Faster Slower. The more data is backed up, the longer the backup takes
Space Taken Depend on the snapshot number and the data volume has changed VM backups can take up a lot of your storage space

Overall, snapshots are very convenient for quick testing and troubleshooting, but cannot be use as a long-term way to protect data from disaster. So they are not recommended for production environments.

Meanwhile, virtual machien backups can be used as a long-term, fixed data protection measure. If there are risks that your VM disks may be deleted or the VM infrastructure may fail, VM backups may be safer.

The following content will focus on the classification and methods of VM backup. In practice, however, you can also combine backups and snapshots as you wish.

How to Choose Virtual Machine Backup Solution Properly

Virtual machine backup methods can be divided into many types from different perspectives, which also creates some difficulties for users to understand. But in terms of how it works, you basically only need to consider the following two main types regardless of the hypervisor: file-based backup and image-based backup.

✎Image-based backup (via agentless backup software): Back up the entire VM, including operating system, config files, and all data on disk. With it, you can achieve fast disaster recovery and get immediately usable VM.
✎File-based backup (via agent-based backup software): Back up a VM as physical machine by installing Agent on each guest machine. You can choose certain files to back up flexibly, but when restoring you need to create an empty new VM first and then install the agent on the guest machine to restore the data.

Usually when IT staffs talking about Hyper-V or VMware virtual machine backup, they mean image-based backups. This is due to a lower tolerance for downtime and a higher need for rapid recovery in production environments.

But beyond that, you may need to consider more granular backup categories and needs in order to create a VM backup strategy that better suits your actual needs.

Virtual Machine Backup Software

Other common VM backup needs you may consider

👉 Different backup method

◇ Full backup: Complete backup of the operating system, applications, and all data on the virtual machine.
◇ Differential backup: Back up only the data that has changed since the last full backup. Restore requires the full backup which was the differential base, and the last differential backup.
◇ Incremental backup: Back up only the data that has changed from the last backup. Restore requires the full backup which was the incremental base, and all incremental backups.

👉 Backup to different storages

◇ Local backup: Store the VM backup files in the local path of the host.
◇ Remote backup: Store the VM backup files in the remote server, for example, a network share, or cloud.

👉 Different backup frequency

◇ Immediate backup: Backup virtual machine once by manual operation.
◇ Regular backup: Create a backup schedule to perform automatic virtual machine backup.

Next, I will present an image-based virtual machine software that meets all these needs for VMware and Hyper-V.

FREE Image-based VM Backup Solution for VMware ESXi and Hyper-V

Image-based virtual machine bakcup is usually achieved by agentless backup software, which can centralize the backup job in a single console without deploying agent program to each VM.

There are indeed some native backup options that can do something close to image-based backup, but they are more or less deficient, for example, you need to power off VM beforehand, you can only back up only one VM at a time, you cannot automate backup, etc.

Therefore, many IT staffs turn to a dedicated virtual backup software. Here I introduce you AOMEI Cyber Backup, the free VM backup software. It offers you the following benefits:

✦ Agentless Image Backup: create independent and image-based backup for VMware ESXi and Hyper-V VMs.
✦ Various Backup Methods: Besides full backup, you can perform incremental or differential VM backup to capture only changed data and save storage space.
✦ Automated Hot Backup: create backup schedules to auto backup running VMs without interference.
✦ Restore from Any Point: Restore a whole VM to usable state from any history backup version.

AOMEI Cyber Backup supports VMware ESXi 6.0 and later versions, as well as Hyper-V in Windows 8/8.1/10/11, Windows Server/Microsoft Hyper-V Server 2012 R2 and later versions.

In next section I will demonstrate how to create an automatic ESXi or Hyper-V VM backup task. You can click the following button to download the free edition.

Download FreewareVMware ESXi & Hyper-V
Secure Download

*You can choose to install this VM backup software on either Windows or Linux system.

3 easy steps to create automatic backup tasks of multiple VMs

1. Bind Devices: Access to AOMEI Cyber Backup web client, navigate to Source Device > VMware ESXi/Hyper-V > + Add VMware ESXi/Hyper-V to add a host. And then click > Bind Device.

Add Hyper-V host

2. Create Backup Task: Navigate to Backup Task > + Create New Task, and then set up Task Name, Backup Type, Device, Target, and Schedule as needed.

Create a VMware ESXi backup task

  • Device: cover multiple VMs (10 on Free Edition) on the host in one backup task.
  • Target: You can select to back up to a local path, or to a network path. Used paths will be saved in Favorite Storage for handy selection.
  • Schedule: You can choose to perform full, differential or incremental backup, and automate execution daily, weekly or monthly according to the frequency you specified.

Schedule type

3. Start Backup: Click Start Backup and you select Add the schedule and start backup now, or Add the schedule only.

Start Backup VMware ESXi VMs

Created backup tasks will be listed and monitored separately, for progress checking and schedule changing.

While the Free Edition covers most of VM backup needs, you can also upgrade to enjoy:
▶ Backup cleanup: Configure a retention policy to auto delete old backup files and save storage space.
▶ Restore to new location: Create a new VM in the same or another datastore/host directly from the backup, saves the trouble of re-configuring the new VM.

Backup Cleanup

Updated: How to Backup Virtual Machines with Built-in Options

As said above, there are some native backup options come with the hypervisor. They may be somehow different from backups in a strict sense, but they do provide a degree of data protection.

Next I will use VMware and Hyper-V as examples for a brief explanation. You can click on the anchor text to jump to corresponding part.

-> VMware ESXi VM backup (2 methods)
-> VMware Workstation VM backup (3 methods)
-> Hyper-V VM backup (2 methods)

Built-in options for VMware ESXi virtual machine backup

As one of the most popular type-1 hypervisor, VMware ESXi offers you some convenient options to save or deploy virtual machine. Here I will introduce 2 frequently used methods:

Method 1. Manually download VM files: ESXi Web Client allows you to download all the VM files, including VMDK virtual disk file and VMX configuration file from datastore. Then you can upload the files and register a new VM.
Method 2. Export VM to OVF template: OVF is a file format that supports exchange of virtual appliances across products and platforms. You can achieve faster downloads with the compressed OVF files.

👉Method 1. Manually download virtual machine disk files from VMware ESXi

1. Access ESXi Web Client, commit all snapshots and power off the virtual machine you want to back up.

2. Turn to Storage page, click Datastore browser on toolbar. Locate the folder of the virtual machine you want to back up, and click Download to download them separately to local.

Download VM files

4. Close Datastore browser window, and you can see the progress in Recent tasks.

👉Method 2. Export the virtual machine as OVF template

1. Access ESXi Web Client, commit all snapshots and power off the virtual machine you want to back up.

2. Go to Virtual Machines page, right-click the virtual machine you want to backup and select Export. Click OK to confirm it.

Select Export option

3. Select Save File option twice to download the .ovf file and .vmdk file. Then click OK to close the window.

When it’s done, you can click download button on toolbar to find where these files are stored.

Built-in options for VMware Workstation virtual machine backup

The backup options in VMware Workstation are similar to ESXi, and you can find an additional feature - VM cloning. Let's take a look at them:

Method 1. Manually Copy VM Disk Files: By manually copying the workstation VM files and storing them additionally, you can restore the VM by opening them directly on workstation.
Method 2. Export VM to OVF Template: Open Virtualization Format (OVF) is a file format that supports exchange of virtual appliances across products and platforms.
Method 3. Clone VMs: Clone is a way to create multiple same VMs. There are 2 kinds of VM clone - a full clone takes long time to create, while a linked clone depens on the parent VM.

In this section, I will demonstrate how to use these ways to backup VMware Workstation VMs.

👉Method 1: Manually copy virtual machine disk files

​1. Launch VMware Workstation, move the cursor to the name of the VM you want to backup. There will be a box showing the folder path where the virtual disk files and configuration files of this system are stored.

Virtual Machine Path

2. Come to the folder, and then copy all files or the whole folder to the destination location where you want to store the backup.

Copy Files

Note: In this way, you need to manually copy your VM data regularly, to keep the backup always new.

👉Method 2: Export virtual machine to OVF template

1. Launch VMware Workstation, select the target VM, and click File on the toolbar, select Export to OVF…

Click Export to OVF

2. Select a path where you want to save the OVF template file in the pop-up window, and then click Save.

Select Export path

3. Wait for the Export process. The more software you installed in this system, the more time this process will cost.

When it’s accomplished, you will find 3 files in destination location. The manifest file ends with .mf, the OVF file which provides a complete specification of the virtual machine, and the virtual disk file ends with .vmdk.

Exorted virtual machine files

Tip: You can also backup VMware Workstation VM by manually copy disk files or clone.

👉Method 3: Clone your virtual machine

1. Launch VMware Workstation, select the VM you want to clone.

Then click VM button on toolbar, and select Manage > Clone… to open Clone Virtual Machine Wizard. Click Next in the pop-up window.

Clone

2. Designate Clone Source. You can choose to Clone from the current state in the virtual machine, or from an existing snapshot (powered off only). If you select the upper one, workstation will create a snapshot before cloning it; if you don’t have a usable snapshot, the second choice will be unselectable.

Clone From

3. Click Next to continue, and designate Clone Type. You can create a linked clone, or create a full clone.

Clone Type

4. Provide the name and storage path of your clone. Then click Finish.

Built-in options for Hyper-V virtual machine backup

Although with different hypervisor, the way Hyper-V virtual machines are backed up is also similar to VMware:

Method 1. Export Hyper-V VMs: Export VMs to OVF or OVA templates in Hyper-V Manager.
Method 2. Windows Server Backup: Windows Server Backup (WSB) is a built-in feature allows you to schedule automatic backup tasks of multiple Hyper-V VMs.

👉Method 1: Export Hyper-V VM via Hyper-V Manager

1. Launch Hyper-V Manager. Right-click the VM you want to backup, select Export…

Select Export

2. Click Browse to specify where you want to save the files in the pop-up window.

Browse

3. Wait for the Export progress to complete. The more software you installed in this system, the more time this process will cost. When it's done, you will find 3 folders in the destination location - the VHD files, VM configuration files, and the snapshots.

👉Method 2. Backup VMs using Windows Server Backup

You can also use the built-in backup utility Windows Server Backup for Hyper-V VMs. Try following steps:

1. Launch Server Manager. Click Manage -> Add Roles -> Features -> Next -> Role-based or feature-based installation -> Next. Select the Server from the server pool and proceed to Features page, find and check Windows Server Backup in Features list to install.

Install Windows Server Backup

2. Then you can click Tools and access Windows Server Backup. Choose Backup Schedule or Backup Once according to your needs. Here take Backup Once as an example.

3. Follow the Backup Once Wizard to make your choice. In Select Backup Configuration page, you can select Custom to choose a specific folder or files. Then click Next.

Select Backup Configuration

4. Click Add items to select the Hyper-V VM you want to back up, and specify a Destination Type and in the next step. You can choose backup Hyper-V to local drive or network share.

Click Add items

5. After selecting a Destination location, you can confirm the settings and click Backup to start.

Summary

Virtual machine backup is one of the most basic measures to ensure VM data security. In this article, I introduced what is virtual machine backup, how can you pick a VM backup solution properly, and how to create backups for VMware and Hyper-V VMs.

Besides, as another failsafe measure, please note that VMware snapshots cannot be used as backups, or you may result in data loss.