From vStorage to snapshots -- solving virtual server backup challenges

Backup has traditionally been one of those critical, yet often thankless tasks. It didn’t garner much attention unless it was impacting server and application performance, or IT wasn’t able to recover important data. With the advent of server virtualization, unfortunately both situations occurred with more frequency – and suddenly backup stepped into the spotlight.


Sever virtualization impacted application performance as multiple VMs tapped the resources of their physical host during backups, and some hypervisors were unable to support application and data consistency upon restore. The latter in particular was a show-stopper for mission-critical environments.


No matter what hypervisor you used, or the method you chose to back up your virtual servers (and there are a number of methods out there), it’s likely that you’d encountered one or both challenges. Some virtualization vendors have delivered new features to help resolve these issues. The VMware vStorage API for Data Protection (VADP) in particular has streamlined the backup and recovery process in VMware environments. (For more information on Data Protector support for VMware environments, including VADP, check out our blog on the HP Data Protection Community Forum.)


So as virtualization technology continues to evolve – what factors should you consider when designing a complete virtual server protection strategy? And how does your backup software fits into the picture?


Companies have a number of virtualization vendors from which to choose – and many IT organizations are deploying two or more hypervisors to suit different needs. VMware is widely acknowledged as the leader in data center virtualization because of the breadth and maturity of the enterprise tools they offer. We also see Microsoft Hyper-V appearing in more remote or branch offices where customers still want virtualization to provide high availability and save on hardware costs. Citrix XenServer also appears frequently in medium and large enterprises as virtualized desktops begin to take hold as the 2nd big virtualization wave. Desktop virtualization promises to relieve some of IT’s biggest pain points such as visiting the desktop to perform hardware upgrades and protecting data on local hard drives.


In addition to choosing the right virtualization vendor for the task, each hypervisor comes with its own set of tools and methods for protecting virtual machines. Some of the most common methods for protecting virtual machines are:


  • Traditional backup – installing an online backup agent inside the virtual machine
  • Console-based (server-based) snapshots
  • Use of a proxy server
  • Array-based snapshots


Traditional backup involves installing a backup software agent inside the virtual machine and executing backup and recovery just as we would in the physical world. This method applies to any hypervisor. It’s exactly what we do in the physical world, and it’s still the most common method for backing up virtual servers – often simply because it’s familiar. In addition, before recent evolutions in virtualization technology, it was a reliable method for delivering a consistent backup. However, traditional backup still places a load on server performance. In mission-critical environments where IT staff are running 10-to-20 virtual machines in a physical server, this method isn’t a viable option.


Some hypervisors have the ability to take snapshots of data on virtual machines. The snapshots are then stored on disk or can be moved to tape for long-term storage or recovery as needed. The method differs depending on which hypervisor – or hypervisor version – you’re using. The snapshot can be executed from the hypervisor console and may require an online backup agent installed in the host operating system. Many organizations leverage the ability of their backup software to automate execution of server-based snapshots. This allows IT staff to manage backup and recovery operations across physical and virtual servers from a centralized console. It saves time and resources, and ensures that backup policies are implemented uniformly throughout the organization. However, there are a couple of challenges associated with console-based snapshots:  they impact server performance and – with some hypervisors – applications running on certain platforms can’t be backed up live using this method and must be suspended in order to perform the backup. For business- and mission-critical environments, that’s not a viable option.


In addition, VMware can leverage proxy servers to avoid the impact of virtual server backup on production applications. Using either VMware Consolidated Backup (for which VMware announced its end-of-life earlier this year) or VADP, the processing load is moved onto a dedicated server – or to the backup server. This minimizes the load on the physical host and its applications. If you’re using VADP, you’ll also get consistent backups.


Finally, we have array-based snapshots. Snapshots have been around for years. In fact, HP Data Protector software customers have been deploying array-based snapshots as part of a total data protection strategy since 1997. If implemented correctly, array-based snapshots provide two enormous benefits in a virtual environment   1) it essentially eliminates the backup window for any hypervisor and allows IT staff to protect data as often as they like and   2) it enables faster recovery for business- and mission-critical applications.


Backup software integrates with the storage system to move the processing load off the virtual server and onto a disk array, where a snapshot or full copy of the data is created at very high speed. The backup software then performs backup operations on the copy, rather than the original data. This staged process allows you to keep business applications online 24x7 without impacting server performance. Snapshots can then be maintained on the array for recovery. For organizations that may not be running the latest VMware hypervisor technology (i.e. VADP), this method also provides consistent backups.


In some cases, some HP customers use array-based snapshots to not only protect data, but to move it around at will – at any time of the day – for reporting, development and test purposes.


The bottom line is that there are lots of ways to back up and restore virtual servers depending on your cost requirements, the recovery needs of your application, as well as what platform or hypervisor you’re using. So in the complex world of virtual server backup, here are a few things to consider:


  • Choose the right hypervisor and virtual server backup method for the appropriate class of data – one size does not fit all
  • Make sure that your backup software provides one central console from which to manage multiple hypervisors, multiple virtual server backup methods, AND physical sever protection
  • Make sure that your backup software supports a broad range of recovery point and time objectives to suit any application


HP Data Protector software backs up and restores any virtual server across a wide variety of platforms and hardware, and simplifies physical and virtual server backup from one easy-to-use interface.  


Together with HP StorageWorks, Data Protector offers a powerful and unique data protection solution for VMware and Microsoft® Hyper-V environments in particular. Data Protector delivers advanced snapshot-based functionality, including fully automated down-to-the-second recovery, without scripting. Unlike other solutions, all of these tasks can be managed from the HP Data Protector interface without the need for scripts or other utilities.


As server and desktop virtualization continues to evolve, don’t forget that it can impact your data protection strategy as well. Recent improvements to virtual server technology have greatly improved backup processes, but a one-size-fit-all answer doesn’t exist when it comes to hypervisors. Incorporating a centrally-managed, tiered data protection strategy for your physical and virtual servers will save time and possibly heartache later.


Check out the HP Software & Solutions Data Protection Community for blogs on HP Data Protector support for VMware and Microsoft Hyper-V environments. Or check out the HP Data Protector software webcast: Best Practices for Data Protection in a Virtual World.


Don’t miss a thing. Get the latest information on HP Data Protector software.

Join the conversation on Twitter and Facebook.

Register today to receive the HP Information Management Digital Hub newsletter.

| ‎04-05-2011 11:26 AM

Data Protector 6.2 is here!  For more information on how Data Protector simplifies application protection in vitual and physical environments -- including simplified snapshots, more disaster recovery functionality, and more check out Data Protector on the HP Information Management Hub.




Leave a Comment

We encourage you to share your comments on this post. Comments are moderated and will be reviewed
and posted as promptly as possible during regular business hours

To ensure your comment is published, be sure to follow the Community Guidelines.

Be sure to enter a unique name. You can't reuse a name that's already in use.
Be sure to enter a unique email address. You can't reuse an email address that's already in use.
Type the characters you see in the picture above.Type the words you hear.
Showing results for 
Search instead for 
Do you mean 
About the Author

Follow Us
The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the Terms of Use and Rules of Participation.