To save the time and disk space spent on VMware VM backup, taking incremental backup sounds like a good option. In this article, I will introduce 4 different types of it and analyzes how to set up a good backup strategy.
Backup has become one of the most important tasks for any data administrator, especially for enterprises. VMware VMs, for example, have a large amount of critical business data that needs to be backed up regularly.
Among VMware backup stratigies, incremental backup is a good virtual machine backup choice because it saves both backup time and space.
How does VMware incremental backup work?
Compared to full backup, VMware incremental backup uses Changed Block Tracking (CBT) technology, and copies only the VM data that has changed since the last backup. Needless to say, it consumes less backup time and takes up less storage space.
When restoring, a large number of restore points allows you to restore the VM to any point in time you want. And features like VMware Consolidated Backup (VCB) enables you to consolidate full and incremental backups into a single backup file that can be restored as a whole.
| Full backup vs incremental backup vs differential backup | ||||||||
| Backup Types | Source | Backup Files | Backup Speed | Space Taken | Restore | Restore Speed | Frequency | Restore Points |
| Full Backup | Entire VM | All VM files | Low | High | Last full backup | High | Low | Few |
| Differential Backup | Last full backup | Changes since last full | Medium | Medium-High | Last full + last differential | Medium | Medium | Medium |
| Incremental Backup | Last full or incremental backup | Changes since last backup | High | Low-High | Last full + all incrementals | Low | High | Many |
VMware offers serveral backup methods to meet different data protection needs. Unfortunately, none of them can actually backup VMware ESXi VMs in incremental way.
You may think of snapshots, which preserves the current state of the VM and incrementally store the later changes to a delta disk. But VM snapshot and backup are quite different. First of all, it still depends on virtual machine's parent disk and cannot be used as an individual backup. Second, keeping snapshots for long time or just taking too many may affect the performance of your VMs.
At the same time, many third-party backup products on the market can achieve VMware incremental backup with more reliable options. You may even be confused by the technical terminology involved. So here I've briefly listed 4 types of incremental backups that you may see, namely, forever incremental backup, conventional incremental backup, forever forward incremental backup and reverse incremental backup.
AOMEI Cyber Backup is a professional and reliable free VMware backup software that offers backup scheme to solve your problem. It supports ESXi 6.0 to 7.0 and Windows Server 2012 and above. It can help you create a perfect incremental backup task.
AOMEI Cyber Backup supports both paid and free versions of VMware ESXi 6.0 and later versions. Next, I will show you how to use AOMEI Cyber Backup for incremental backup in 3 simple steps. You can click the following button to download the freeware.
1. Download AOMEI Cyber Backup. Install and launch it. *You can choose to install this VM backup software on either Windows or Linux system.
2. To create wonderful backup tasks, you could navigate to Source Device and click VMware >> Add VMware Device to add vCenter or Standalone ESXi host as the source device. Enter IP address or device name, and type the User information including device username and password. Click Confirm.
3. Bind your device to AOMEI Cyber Backup, and start creating your backup task.
4. In Backup Task page, click Create New Task to set up your backup plan.
☞ Task name: enter a backup task name.
☞ Backup Type: choose VMware ESXi Backup or Hyper-V Backup as you want.
☞ Device Name: select the device and virtual machines you want to back up. Click OK.
☞ Target: choose a location to store your backup files. You can choose a local path or a network path. Click OK.
Notes: If you choose to create a network path, you need to enter the path first and click the button on the right side to verify authentication which requires you to enter the user name and password of the network path, or you can try logging in anonymously.
☞ Schedule: Click Enable Schedule to start scheduling your backup tasks. In Backup Method drop-down options, 3 backup method for you such as Full Backup, Incremental Backup, Differential Backup. In Schedule Type drop-down options, specify the backup time period such as daily, weekly, monthly (by week), monthly (by data).
Tips: Incremental backup only backs up the changed data compares to the last backup. If you need to delete one of the full backups or one of the incremental backups, all the associated backups after this one need to be deleted.
☞ After setting up all information, click Start Backup to finish the process of scheduling incremental backups.
When enabling the backup task, you can check the status in the Backup Task screen, and edit the settings by clicking “…” on the right side of task.
While the Free Edition covers most of VM backup needs, you can also upgrade to Premium Edition to enjoy: ▶ Batch VM Backup: batch backup large numbers of VMs managed by vCenter Server or standalone ESXi hosts. ▶ 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.
According to your own needs, such as recovery time objectives (RTO), restore point objectives (RPO), and risk tolerance, etc. Ask yourself what you need and how to choose a suitable VMware backup strategy?
For example, how much data can you tolerant to lose? A year’s data, a month, a week, a day, or an hour? If you perform weekly backups, the worst situation is that you could lost one week of data. Is it tolerable for enterprise? If not, then you may consider to perform daily backups, but the daily backup requires so much time and storage spaces, it may be low-efficient and expensive.
Especially for enterprise, it requires a high backup frequency. Among multiple VMware backup solutions, AOMEI Cyber Backup offers greatly simplified backup steps and save costs.
| Backup Frequency | Backup Strategy |
| Monthly/Yearly or less | Full backups |
| Weekly | Full backups |
| Daily | Weekly full backups + daily differential |
| Hourly | Weekly full backups + daily differential + hourly incremental |
To meet different demands, some of backup software develop various types of VMware incremental backup. In this section, I will introduce another 3 different types of VMware incremental backup.
The forever incremental backup means to only perform one full backup at the beginning, and all subsequent backups are incremental.
As a result, the recovery progress can be extremely slow. To provide a valid restore image, the backup software first needs to take the full backup and apply all the changes saved in the incremental backups.
In addition, corruption of a single incremental backup file can lead to the failure of the entire subsequent backup chain, so there is a risk of data loss.
The forever forward incremental backup means to set a retention policy, to merge the earliest incremental backup into the first full backup, whenever the number of the subsequent incremental backups exceed the number required by the retention policy.
The best feature of this way is that it saves disk space and backup-restore time. However, it can only maintain a fixed number of restore points. And if additional full backups are performed while forever forward incremental backup is enabled, it may reset the backup chain.
The reverse incremental backup means to create a full backup at the beginning, and all subsequent incremental backup will be merged into this full backup to keep it up-to-date, meanwhile the reverse incremental backup files will be saved as restore points for you to restore to previous state.
This offers a fast way to restore your VM to current state, but if you want to restore to an earlier restore point, you will lose the advantage of faster recovery. And incremental backups will still take up some disk space.
In this article, I introduced the detailed steps to achieve VMware incremental backup using AOMEI Cyber Backup in VMware and also explains 3 different types of incremental backup for you.
A good backup tool can ensure your VM data security, improve work efficiency, and save costs on storage and time. If you also want to perform VMware ESXi bare metal backup, this software is still helpful to solve your problem.