The architecture of a virtual machine differs vastly from traditional on-premises environments, and requires different data backup techniques and pre-backup operations. This post will explain some of the things administrators have to keep in mind before backing up their VMware virtual machines.

1. Back up VMware virtual machines at the virtualization layer.

When backing up traditional physical servers, it is customary to install a backup agent on the guest operating system. The backup server then contacts the agent when it is about to initiate a backup operation. This method isn’t efficient in a virtual environment, as it unnecessarily consumes resources on the VM and impacts the performance of the VM and all other VMs in the host.

Make sure that your virtual machine backup tool can back up your virtual machines at the virtualization layer. This means using a backup application that performs image-level backups of the large .vmdk file without involving the guest OS. This will ensure your VMs get all the resources they can for their workloads.

2. Quiesce your transactional applications.

If you’re going to back up a VM that has transactional applications like databases and email servers, it’s critical that you quiesce them so they are in the proper state to be backed up. This ensures the server is in a proper state so no data is lost if a restore is needed. 

VMware Tools contains a driver that works with Microsoft Volume Shadow Copy Service (VSS) to quiesce applications before they are backed upAlso, make sure that the VSS service isn’t disabled and everything is configured properly to perform an application-consistent backup.

3. Don’t skimp on backup resources.

Before you back up a virtual machine, make sure that you have adequate storage space in your repository. Having adequate CPU and memory resources is critical, and can significantly impact how long the backup takes. Make sure you follow the backup vendor’s hardware recommendations for the backup server. 

4. Don’t store backups with production data.

Don’t keep all your eggs in one basket. Don’t use the same repository to store your backups and your organization‘s other sensitive data. Any problem that might occur in your repository would not only rob you off your organizational data but also all your virtual machine backups.

The cost per gigabyte stored, which has become cheaper than what it was just half a decade ago, is dropping even lower with advancements in cloud storage. It is prudent and effective to isolate your production and backup data, and also have an offsite backup for both.

5. Schedule backups carefully.

The process of taking a backup can strain the resources on a virtual machine host and might impact the performance of the other virtual machines in the host. 

For this reason, you should plan your backup schedule to avoid putting too much stress on your virtual machine host. It’s best to perform backups during non-business hours. Also, make sure not to back up too many VMs on the same host concurrently. Balance your backup schedule to even out your resource usage.