Interviews

posted on 12 August 2008 08:16

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Blocks and Files had the opportunity to quiz Revinetix' VP of engineering, John Robertson, about deduplication and compression issues. Earlier this month Revinetix added file-level duplication capability to the operating system, RevOS, in its disk-to-disk (D2D) backup and archiving appliances. This prompted us to wonder about the company's views on sub-file level deduplication, cloud backup and other topics. We asked the questions and here are the answers.

Blocks and Files: Will Revinetix add sub-file-level deduplication?

John Robertson: Before filing the patent on our deduplication technology, we carefully considered block-level versus file-level processing. Our customer feedback and research indicated we should prioritize developments on file-level deduplication. A primary reason for preference to file-level deduplication is the faster performance over block-level deduplication. As such, it is a key feature of our recent RevOS 3.0 software upgrade based upon that input. Before we move to sub file-level deduplication we must confirm there is a significant benefit on real world data above file-level deduplication to our customers. Short answer…Revinetix is investigating methods for overcoming sub-file-level performance issues. Stay tuned.

Blocks and Files: Would this be deduping at data ingest time or post-process?

John Robertson: Our RevOS 3.0 performs deduplication after the files are received from the backed-up devices (i.e. post-processing). This ensures that all data is backed up as quickly as possible, minimizing the backup window, at the expense of temporarily duplicated disk space and duplicated network bandwidth. In other words, the RevOS appliance requires some extra temporary working space. One advantage to post-processing is the ability to achieve better deduplication over multiple boxes. We are developing additional technologies to address both efficient disk utilization as well as efficient network utilization.

Blocks and Files: What kind of dedupe ratios might be achievable?

John Robertson: Conservatively, we plan with our customers for a 3x increase of their retention policy, but find that most sampled experience between 6x and 9x increase. Actual improvement, of course, varies by industry and organizational policies.

Blocks and Files: What does the firm think of HW deduplication?

John Robertson: Revinetix focuses on moving quickly to solve business needs. Our expertise is primarily focused on developing software technologies while fully leveraging available and robust hardware technologies. This has allowed us to focus on and solve broader disaster recovery solutions for SMB and SME customers. Hardware dedupe devices provide an excellent, complimentary solution to efficient and secure storage.

Blocks and Files: Does the firm use hardware compression?

John Robertson: RevOS utilizes software compression. We’re investigating the use of RAID based hardware compression and encryption. As with hardware dedupe, hardware compression is a complimentary technology that can be leveraged to improve our broad business solution.

Blocks and Files: Does Revinetix have thoughts about adding a backup-to-the-cloud capability to its product line through a tie up with a cloud backup service provider such as Nirvanix or Spare Backup?

John Robertson: Good question. Our current market predominately requires strict control of their data. Even so, we do believe that our technology would viably support a cloud backup environment. We are investigating and remain open to these arrangements. Maybe we can get you to do some introductions for us. (!)

Blocks and Files: Does Revinetix think appliance contents encryption might be necessary at some point?

John Robertson: We believe encryption of archive disks to be essential to protecting data. Revinetix RevOS has supported encryption of archive disks since 2006. This continues to be an important feature for our customers.

Blocks and Files: Does Revinetix think replication could be added to its appliances for Disaster Recovery?

John Robertson: It’s already there. Revinetix RevOS includes both mirroring and replication of backup and recovery data. We find this continues to be an important selection criterion for our customers.

Commentary

What we see here is a concern for a balance between backup and archiving speed and the disk store's capacity. This is pretty important for Revinetix' small and medium-sized enterprise customers who do not want backup windows lengthened by their disk backup appliance taking too long to chew through CPU-intensive block-level deduplication. Sure, Revinetix could throw quad-core CPUs at the problem but then costs would go up and, as John Robinson says, the firm wants to be positive that there are real benefits to its customers here.

The appliances already encrypt data and replicate it to provide a secured business continuity and disaster recovery capability. In the future there may be a case for replicating into the cloud and so having the security, strict data control, and speed of a local copy and the insurance of a DR copy of the data 'in-the-cloud' through Nirvanix or a vanilla cloud backup service provider such as Spare Backup. But that is a matter for consideration only at this stage of the game.

For SME companies thinking about data protection Revinetix' appliances have a lot of attractive features. Check them out.

^{[Chris Mellor.]}