A good backup strategy is the last line of defense against disasters such as hardware failure, environmental damage, accidental deletions, or misconfigurations. In a virtual environment, a backup strategy can turn into a daunting task because of the number of virtual machines that need to be backed up. In a busy production environment, a new virtual machine can come and go anytime. Without a proper backup plan, the entire backup task can become difficult to manage. Gone are the days when we had only a little server hardware to deal with and backing it up was an easy task. In today's virtual environments, a backup solution has to deal with several dozen, or possibly several hundred, virtual machines.

Depending on the business requirement, an administrator may have to back up all the virtual machines regularly, instead of just the files inside VMs. Backing up an entire virtual machine takes up a very large amount of space after a while, depending on how many previous backups we have. A granular file backup helps you quickly back up user data but provides no protection against entire VM corruption or loss.

Along with a backup strategy, a restore plan is equally important, because a backup is only useful when we can successfully restore data in a timely and proper manner after a disaster. In this chapter, we will cover the following topics:

• Exploring Proxmox backup options
• Configuring backups
• Configuring snapshots
• Restoring VMs
• VM replication
• Backing up a configuration file