ready for a backup.
If you have guest operating systems that can’t use the Hyper-V pass-through VSS
capability, perform backups within the virtual machine. At times, backing up within
the virtual machine gives a better level of functionality, depending on the backup
application. Suppose I want to use System Center Data Protection Manager (DPM),
which is the Microsoft premium backup and recovery solution for Microsoft
workloads. When you have the DPM agent on the virtual server in the main DPM
administrator console, the level of granularity that you have for what to protect would
be at a virtual machine level. You can select which virtual machines to protect, but
that’s all you get. You can’t go into detail about what to protect within the virtual
machine. During a restore operation, you would be able to restore only the entire
virtual machine or files from the VM, but nothing application aware such as restoring
a SQL database or Exchange mailbox.
If you deploy the agent into the guest operating systems, you will have the full
granularity of knowledge that comes with DPM. For example, if the virtual machine is
running SQL Server, you will be able to select the databases to protect and to capture
the transaction logs, and so on. The restore granularity will be the same, enabling the
restore of just a specific database. Likewise, if I backed up a SharePoint server from
within the SharePoint VM, I would be able to perform item-level recovery. Figure 6.4
shows an example with two virtual machines that are protected at the host level and
two other virtual machines that have the DPM agent installed locally, which allows me
to protect application-aware workloads such as Exchange mailboxes and SQL
databases. The same applies when using Azure Backup Server, which is essentially
“DPM Lite” and is available to back up workloads to the Azure Backup service.
Figure 6.4 Example view of protection using DPM
This means that for the best functionality, sometimes performing backups from
within the guest OS gives the best results, especially if your backup software has
application-specific modules. Make sure that you regularly test restoring the backups
you take. Many times I have seen companies try to restore a backup when it’s really
needed, and it fails, or the right information was not being backed up.
Microsoft made big changes to how Hyper-V backups worked between Windows