1. Backing up VMs as physical machines

In theory, from a user's perspective, a VM functions the same as a physical machine. That's why admins can use the same backup procedures. You can download a backup agent and program backups just like you do with a regular machine.

Pros: It is easy to work with and doesn't require any learning curve.

Cons: It protects the OS and apps but not the virtual machine itself. That's why a direct restoration of the whole virtualized environment is impossible.

2. File-based backup strategy

VMware stores each virtual machine as a virtual machine file (mainly a VMDK file). To protect entire VMs easily, you can backup these files. While OS backups tend to consume significant time and system resources, VMDK file backup is a pretty simple and prompt operation.

Pros: It is an easy solution that doesn't affect the guest OS and its applications. Backup takes ESXi server resources.

Cons: It makes a complete snapshot of a virtual machine without the option of removing certain apps or restoring a specific file. Instead, you can only recover the entire VMDK file, which may contain unnecessary and extensive data. Recovery Time Objective (RTO) is generally higher with file-based backup.

3. Third-party backup and restore solutions

The good thing about third-party solutions is that you get an all-in-one approach. Generally, what's offered is:

Application-aware backup
Backup and recovery of full VMs and ESXi hosts or separate files
Instant restoration
Incremental backups using global deduplication to save storage space
Network acceleration to boost the data backup process.