Service provider takeaway: Service providers can solve a number of problems for customers with a new class of devices that promises to ease backup target consolidation via virtualization.
Finally, there's a way around this scenario: A new class of devices on the market address backup target consolidation with virtualization. The devices essentially offload the data movement work from the backup application and create a single virtual point to send the backup data to. They present an ideal opportunity for integrators to show their talents in merging multiple vendor solutions into a single cohesive strategy that increases the effectiveness and functionality of the backup process.
Before I explain exactly how the appliances work, let's talk in more detail about why the status quo isn't great. Today's backup target of choice is disk-to-disk backup. It has passed the functional tests and is widely accepted as the next step in the evolution of the backup process. But most of your customers haven't budgeted for disk-to-disk backup to totally replace tape, just to augment it, so a combination of devices is used. Some customers use disk to solve particular backup problems in a one-shot fashion, and in some cases, there are multiple instances of different disk targets mixed into the process. Even if they've left disk out of the mix or if there's only one instance of it, there are almost always multiple forms of external media like tape and maybe even optical.
This is where backup target consolidation via virtualization comes in. Like server virtualization, backup virtualization enables big efficiencies by creating a single virtual target for backup applications to communicate with, rather than many physical ones. This setup simplifies management of the backup process and makes it more flexible, which is key since backup target technology is constantly changing.
It's important to note that this new breed of backup virtualization appliance -- from companies like Gresham Enterprise Storage, with Clareti Storage Director, and Fujitsu, with CentricStor -- is distinct from virtual tape libraries (VTLs). VTLs are essentially single-purpose disk arrays (backup only) that emulate a disk and have little or no integration with tape. To move this data from the disk device to the tape library, you must create another set of jobs in the backup application. A backup virtualization appliance, on the other hand, sits among the backup server, media servers and backup targets, whether disk, tape or optical. That appliance then presents a single virtual target for the backup software to send data to. From that point, the backup virtualization appliance manages all data movement between backup targets. This integration allows different backup targets to be leveraged for what they are best suited.
For example, the Gresham appliance can move data at 5 TB per hour, enabling a fast disk cache to receive that data. The data could then be migrated to a data deduplication device for medium-term storage and then replicated across modest wide-area network (WAN) connections. It could be further migrated to a deeper disk archive for longer and more scalable storage. The data could also be moved to tape and/or optical media for deep and cost-effective retention of the backup. Throughout this tiered migration, the backup application sees one virtual backup target, keeping its schedule and operation simple. All the policies are applied and data movement is performed by the backup virtualization appliance, not the backup application.
In addition to enabling tiered storage, backup virtualization makes integration and migration to new technology easier. A new backup target can be connected to the backup virtualization appliance and accept backup jobs with no change to the backup software application. If the older technology needs to be removed from the data center, the backup virtualization appliance can migrate that data to the new tape target in the background without disrupting primary backup operations. And new backup applications can be added to the backup virtualization infrastructure easily -- without recabling disk backup and tape library devices or deciding what hardware should be connected to what backup server. The new application can simply write to the new pool. Data management is then handled by the backup virtualization appliance.
Backup target consolidation is an ideal market for integrators. It requires the skill set that typically only integrators have -- the ability to mix different manufacturers' hardware into a single cohesive solution. Now, with backup virtualization, storage integrators finally have a platform that allows them to bring those skills to the forefront.
About the author
George Crump is president and founder of Storage Switzerland, an IT analyst firm focused on the storage and virtualization segments. With 25 years of experience designing storage solutions for data centers across the United States, he has seen the birth of such technologies as RAID, NAS and SAN. Prior to founding Storage Switzerland, George was chief technology officer at one of the nation's largest storage integrators, where he was in charge of technology testing, integration and product selection.
This was first published in July 2008