Microsoft Hyper-V virtual machines can be protected against data loss using the Cove Data Protection (Cove) Backup Manager.
Guest Level Versus Host Level Backups
Hyper-V VM's can be backed up by either of the following methods:
- Guest Level backups - This is the equivalent of backing up a physical machine, where Backup Manager is installed inside the Hyper-V virtual machine and you can standardize backup settings, make data source selections, and apply filters and exclusions to avoid backing up unnecessary data
- Host Level backups - This method is configured at the hypervisor level, where Backup Manager would be installed and you can configure the selection to backup entire VMs, including their configurations and file structure
We strongly recommend using guest level backups as this will give more granularity and flexibility. Guest level backups are also more efficient.
Guest Level Backup Advantage
There are several advantages to using Guest Level backups.
- The use of Cove's Automatic Deployment feature via any remote deployment tool
- The ability to standardize backup settings using Profiles, which would mean no differences between backing up physical or virtual machines
- Improve efficiency by the using filters and exclusions to avoid backing up unnecessary files such as temp and cache files, which result in sending less data and therefore faster backups and restores
- High frequent backups, increase RPO
- No performance impact incurred on the hypervisor
- Simple and fast granular restore to original or alternative location
- Flexible cross platform restore: Virtual-to-virtual or Physical-to-virtual
- Automated Recovery Testing to the cloud and local target available
- Standby Image support to perform a full system restore back into a virtual machine
This can be done as a continuous restore to provide business continuity and increase RTO
Host Level Backup Advantage
Guest level backups are especially useful for Linux VMs, as these cannot use Virtual Disaster Recovery or Standby Image.
Host Level Backup Limitations
We do not recommend Hyper-V or VMware host-level backups even though they are possible for a number of reasons. Several limitations of host level backups are:
- No use of backup filter and exclusion options
- More data is sent during backups due to temporary disk changes
- Hyper-V clusters are not supported, meaning Backup only includes locally hosted Hyper-V VMs
- Running more frequent backups can affect the hypervisor and bandwidth and impact performance
- It is not possible to back up a CSV and non-CSV volume in the same set on Windows Server 2012 and 2012 R2, due to a Windows limitation
- Backups may fail if the selection contains a Hyper-V cluster deployed on Windows Server 2008 R2 or an earlier version
- Limited delta restores when restoring single files/databases
- Restore target is limited to the same hypervisor version
- No business continuity included, meaning delta restores will take same amount of time as initial restore
- Automated Cloud Recovery Testing is not included
- Standby Image is not supported
- It is not possible to restore directly to a CSV
Instead we recommend restoring to the host locally and then moving the VM over via the Virtual Machine Management Service
Due to the nature of Hyper-V backups, if you restart a backup a snapshot remains on the device. This is because the backup was unable to complete and remove the snapshot itself.
These snapshots can be deleted manually.