Virtual Backups

Virtualization is now an integral part of most data center consolidation and green initiatives at many IT organizations. It’s also at the core of technologies such as cloud computing. But while virtualization products such as VMware’s vSphere and Microsoft’s Hyper-V can offer better utilization of computing hardware, virtualization creates another set of challenges for backup and recovery. That’s especially true if you’re trying to manage backups centrally across both virtual and nonvirtual servers.

Until recently, the number of backup server software packages supporting virtual servers was extremely limited, as was their functionality. But now there are a number of backup products for midsize organizations that can tackle virtualization as part of the job, making business continuity easier to manage. One of those products is Symantec’s Backup Exec Agent for VMware Virtual Infrastructure, an add-on to Symantec’s Windows Server–based Backup Exec product line.

Advantages

Symantec’s Backup Exec 2010 Agent for VMware offers a rich set of backup options for virtualized servers. A “single-pass” backup can be used to capture recovery data for all virtual machines on a protected server. If they’re Windows-based machines running applications that leverage Volume Shadow Copy Service, that data can also be captured and backed up in a single pass.

The product’s greatest strength, from a pure backup-and-restore standpoint, is its integration with the VMware vStorage interface, which is part of vSphere. This gives direct access to the storage on all the virtual servers on a managed vSphere host machine, so you don’t need to run agents on each virtual machine session.

This integration lets Backup Exec do incremental and differential backups of virtual machines, and do them directly to a storage area network, tape or disk without having to offload to a proxy. For example, you can back up just what’s changed in the virtual machine based on policies created in Backup Exec’s console. For this to work, you’ll have to configure your virtual machines with Version 7 of VMware’s virtual hardware.

And if those guest VMs are running Windows as their operating system, Backup Exec offers granular recovery technology. This feature, which starts by default in Backup Exec for Windows environments, allows for the incremental backup and restoration of individual files and folders within individual virtual Windows machines without having to perform a full “snapshot” restore of the entire virtual server.

If you’re running Microsoft Exchange, SQL Server or Active Directory applications on a virtual machine, individual items can also be restored to those as well. This eliminates the need for redundant backups of application data on virtual machines.

Why It Works for IT

Backup Exec Agent for VMware supports the full range of VMware’s data center products, including VMware’s ESX Server (v.3.5 update 2 or higher), the vCenter Server management platform (formerly called Virtual Center), and vSphere 4.0. All of these are supported from within the same Windows-based management console used for the rest of your data center. Also, if you’re running a mixed virtualization environment, Symantec also offers support for Microsoft’s Hyper-V virtualization hypervisor. 

If you’re using a backup for disaster recovery, or just want to create a duplicate of a virtual server’s state on another virtual machine, Backup Exec’s Agent for VMware will let you redirect the restoration of data from one virtual machine to an alternative location. You can redirect restores to an alternate folder on the same server, a different data store, an entirely different host on the same network, or even to another network.

Then there’s deduplication of data in backups. The Backup Exec 2010 environment offers integrated deduplication, reducing the storage requirements for backups of virtual environments. It also improves the performance of backups across networks. This can result in a huge savings in storage and bandwidth, as much of what makes up the backup of virtual machines is duplicated across all the virtual machines running on a server.

Disadvantages

Backup Exec is designed for midsize environments — from a few servers up to a few hundred. If you’re dealing with more physical machines, you’ll want to consider Symantec’s NetBackup or another enterprise product.

The Backup Exec server and console tools are Windows-based, and many of the strengths of the Backup Exec tools — like the granular recovery capability — are Windows-specific. While this is certainly an advantage for organizations heavily focused on virtualized Windows applications, they may not make a good match for other organizations.

Also, if you’re not running vSphere for virtualization, you’re not going to get most out of the Backup Exec Agent for VMware. The incremental and differential backup capabilities are wired into the vSphere vStorage engine. Also, the vStorage backup does not allow client/source deduplication, so deduplication has to happen at the Backup Exec server’s own deduplication folder.