You’ve made the move towards virtualizing the data center. Whether it's for server consolidation, faster provisioning, improved business continuity, or a mix of these goals – you’re in good company. In fact, industry analysts estimate that over 50% of organizations are using server virtualization for some portion of their operations.

But how are you protecting these virtual servers and their data?

Most virtualization packages includes some form of high availability add-on that allows virtual machines (VMs) to move between physical resources. But just like in a physical server environment, HA is only one portion of a data protection strategy. You still need a solution to cost-effectively recover from data loss, corruption, and full site outages – not to mention satisfy regulatory compliance requirements.

To meet these needs without squandering your entire IT budget, you need a backup & recovery solution that uses cost-optimized disk (e.g. a de-duplication product) and tape for archiving and long term disaster recovery. But as you have probably already realized, backup and recovery of virtual servers is different than with physical servers.

Quantum can help. Working with industry leading backup applications and server virtualization vendors, Quantum has solutions that easily integrate into your virtual data center and cost-effectively protect your data both on and offsite.

At first glance, data protection within a virtual data center can be performed exactly the same as in a physical environment. As shown in Figure 1, a backup agent can run in a guest OS and then data can be pushed to a backup server connected to either a tape library or disk-based backup device with de-duplication like Quantum’s DXi. In fact, it is entirely possible that a virtual machine could connect directly to a backup device as in Figure 2.

Figure 1.

Figure 2.

The obvious benefit of this strategy is that it leverages all of your existing processes and expertise. Unfortunately though, it does not account for some of the issues that sharing physical resources can cause. As shown in figure 3, virtual servers share the underlying physical resources of a server. If one VM consumes the bulk of these resources, say for an active backup job, then other VMs become resource starved.

While many virtualization packages offer functionality to migrate VMs between physical resources to handle these issues, it is important to check how that can affect applications and backup jobs. In fact, moving a VM could prevent a backup job from running properly. So, before using any form of migration functionality, its critical to understand how it will impact the ability of data protection operations to run.

In addition to resource allocation and VM location, another key factor to consider is protection of the actual virtualization layer. Some vendors recommend backing up the virtualization layer to make restoration easier in the event of a full disaster recovery. In this case, your data protection strategy will grow and include more jobs (VMs plus virtualization layer).

To recap, the most common data protection challenges in a virtual server world are:

• Resource allocation & preventing VM starvation
• VM locality impact on backup jobs working
• Adding new jobs to protect the virtualization layer

As covered in “The Challenges of Protecting a Virtual World” performing backup and recovery on virtual servers is not always completely straight forward. To help customers, Quantum offers the following tips and tactics. For more detailed assistance in how to best protect your virtualized data center, contact a Quantum sales representative today.

Tip 1: Leverage the Virtualization Software Vendor’s Strengths
Companies like VMware often provide utilities to help simplify the process of protecting virtual environments. VMware’s VCB uses snapshot technology to eliminate resource overhead and create images which can then be backed up by another application like BackupExec, Commvault, or VizionCore. Of course you should always understand the specifics of how these packages work. For instance, VCB requires a shared SAN resource and currently only offers incremental backup functionality for Windows VMs.

The counter is also true. There can be limitations or specific requirements to performing VM data protection. For instance, some virtualization products do not include snapshot functionality. In this instance a VM must be backed up using either standard backup software or by backing up the VM “disks” and the associated configuration files. This method usually requires the virtual machine to be shut down before running the backup. This may even be true when using expensive and complex array-based techniques (e.g. mirror splits). To prevent undesired performance issues or outages during backups, talk with your virtualization vendor.

Tip 2: Determine What is Best for the Application
Backup application vendors have years of experience handling database and email applications that need to be quiesced or tracked carefully to allow for a coherent and consistent backup. For these application types it may be best to continue to use an agent based backup approach – even if other backup and recovery functions are provided by the virtualization software vendor.

Tip 3: Plot Resource Utilization Windows
For those VMs that will use a traditional agent based approach to backups, make sure you understand how much of the physical server’s resources will be consumed by the backup and for how long. With this information you can plot in advance how many VMs should reside on the physical servers or if VM migration strategies and hard resource allocations are necessary.

Tip 4: Understand How Virtual Your Virtual World Really Is
Always make sure you understand how migration of virtual machines will impact backup and recovery processes – whether the backup and recovery is done via a traditional agent based approach or a virtualization vendor specific process like VCB. Also be sure to understand how important it is to backup and restore the virtualization layer itself.

Tip 5: Make Sure Your Strategy Covers Every Server – Virtual and Physical
Most of the popular virtualization software packages available today are aimed at either high end UNIX systems or x86 based operating systems, typically Windows. As a result, many consumers find themselves with a data protection strategy that covers both VMs and physical systems. Work closely with your backup application and hardware providers that have knowledge of how to handle mixed environments like this.

Tip 6: Save Your Dollars, Euros, Yen
One of the key value statements of virtualization software is to reduce costs and optimize resource utilization. The same should be true of your data protection strategy. That’s why de-duplication products like Quantum’s DXi line fit so well into virtual data centers. The DXi offers capacity optimized storage, multiple presentations (NAS, VTL, iSCSI, FC), and encrypted, low-bandwidth replication to serve a variety of onsite and offsite data protection needs.

As data levels grow, tape is still the most cost effective and reliable method of preserving data. Quantum understands this and supplements the DXi line with a wide range of tape devices that support encryption so that you can protect and archive data at extremely low costs while avoiding the issues that have plagued offline storage in recent years.