I recently blogged about the big changes In WS2012 Cluster Shared Volume (CSV). The biggest changes are related to backup:
- Single coordinated VSS snapshot
- No more redirected IO
In Windows Server 2008 R2 CSV backup, we tried to use a hardware VSS provider to reduce the impacts of redirected IO. But as it turns out, the multiple-snapshot-per-backup process of the past could cause problems for the hardware VSS provider and the SAN snapshot functionality. In extreme cases, those problems could even lead to a CSV LUN “disappearing”.
If you had these problems and couldn’t get a better hardware VSS provider then you would switch to using the system VSS provider (using the VSS functionality that is built into Windows Server and does not use SAN snapshot features). You’d be forced to use the system VSS provider if your SAN did not have support or licensing for a hardware (physical SAN) or software (software SAN) VSS provider.
If you were using the system VSS provider to backup W2008 R2 CSV then Microsoft recommended you to do something called serialization of your CSV backup (see here for DPM 2010 instructions). This process creates (using PowerShell) and uses an XML file that is read by DPM. Nice and simple if you have one DPM server for every W2008 R2 Hyper-V cluster. But what if you had lots of clusters backed up by a single DPM server? It meant you had to manually merge the XML files, and that would be a nightmare in a cloud where there is nothing but change.
Microsoft has released the System Center Data Protection Manager CSV Serialization Tool to help you in this scenario. This tool is intended to be used when backing up Windows Server 2008 R2 Hyper-V clusters with one or more CSVs using DPM 2010 with QFE 3 and above or DPM 2012.
You do not need to use this tool with WS2012 CSV.
The downloads include the PS1 PowerShell script to create an XML file for each cluster and a tool to consolidate those XML files for DPM to use.
Why release this tool? Lots of people will have W2008 R2 clusters and won’t be in a position to upgrade them now or ever:
- Change to production systems can be restricted, e.g. pharmaceuticals.
- They might have licensed without Software Assurance and can’t upgrade their hosts until there is licensing budget.
- They might build new clusters/hosts using WS2012 and have to leave existing VMs where they are until there is a suitable maintenance window. For a public cloud, this could have to be scheduled well in advance.
This free tool will allow those sorts of environments to reduce DPM administrative effort.