Backing up virtual machines (VMs) requires choosing an appropriate strategy. It's possible to back them up similarly to the way physical servers are backed up, but that isn't an optimal solution. The characteristics of virtual machines offer alternative approaches to backup that provide more flexibility and make restoring VMs faster.
Traditional Backup Strategies
The traditional way of doing backups, developed with physical servers in mind, uses one of these approaches:
- Full backups. All files on the server are backed up.
- Incremental backups. Files changed since the last incremental backup are saved.
- Differential backups. Files changed since the last full backup are saved.
Full backups take the most time to create, but are fastest to restore. Using an incremental backup strategy means recovery requires starting with a full backup and restoring all the subsequent incremental backups. Recovery with differential backups requires the latest full backup plus the most current differential. To create the backups, an agent must be installed on each server.
Virtual Machine Backup Strategies
Using virtual machines allows different backup strategies:
- Traditional backup. Use one of the physical server backup strategies.
- Image backup. Create a full backup of the virtual disk file.
- Synthetic backup. Combine the full backup with the changed files to create restorable image.
You can perform traditional backups on a VM by installing an agent on the virtual machine. VM-specific backup tools don't need an agent, instead using the VM's API to identify the changes needing to be backed up.
Backup tools designed for VMs have other benefits as well. By creating a snapshot file, VM backups can be performed without shutting users out of the system. They're able to integrate with the VM management tool and discover VMs and the hosts they run on. This means that a VM's backup strategy doesn't need to be updated if the VM moves to a different physical machine.
Challenges of Combining Physical and Virtual Machine Backups
Using different strategies and different tools for backing up physical and virtual machines allows the backup strategy to be tailored to the data, but can make it harder to monitor the backup process and make sure all machines are being backed up successfully.
It's important, then, to develop a backup strategy that meets the individualized needs of physical and virtual servers without introducing complexity. Using tools such as Veeam, which are designed to work across physical, virtual, and cloud environments, makes it easier to implement backups tailored to each environment without complicating management.
Have you implemented a backup solution that works across all your environments? If you're finding it complicated to meet all your requirements, talk to dcVAST. Our experienced team will help you create and manage a backup process using tools like Veeam Availability Suite. No matter where your data resides, working with dcVAST can help ensure that it is backed up, protected, and ready to help you recover when needed.