Diligent VTL lowers TCO

By Ann Silverthorn

—Proponents of disk-based backup have been trying to improve total cost of ownership (TCO) for a while now. To that end, Diligent Technologies claims to have improved TCO by reducing the amount of disk required for backups by 25x or more with its ProtecTIER platform.

The first access module to the ProtecTIER platform is ProtecTIER VT, which is Diligent's virtual tape solution for open systems. Since virtual tape library (VTL) technology surfaced about a year ago, it has improved backup-and-recovery operations, but it hasn't addressed the fundamental problem of uncontrolled data growth, according to Neville Yates, Diligent's CTO. Because the cost of storing data on disk has been historically higher than storing it on tape, customers have only kept a relatively small amount of data on disk before moving it to tape.

Diligent claims that ProtecTIER decreases the volume of storage required 25x or more by eliminating redundant data. The company estimates that only 1% to 5% of data changes from backup cycle to backup cycle. Using that to its advantage, if the data has been seen before, ProtecTIER stores a reference to that data instead of storing the data itself.

"When ProtecTIER sees new data, it does new computations rather than using data reduction schemes that rely on fingerprints and can cause false positives," Yates explains.

The ProtecTIER platform is designed for open systems, unlike VTL appliances that require customers to purchase specific hardware. It stores data on commodity hardware to reduce backup expenses. The software resides on a standard Linux server and uses Fibre Channel disk arrays as the backup medium.

The disk-based data-protection solution emulates tape libraries. Since it uses less storage space, it allows users to keep data on disk longer, or even indefinitely. It provides "single-instance store" for backup, recovery, archive, and compliance applications, eliminating the duplicate copies of data that result from a typical backup routine.

ProtecTIER is built on Diligent's HyperFactor factoring algorithm, which creates its own computations rather than relying on algorithms such as MD5 or SHA-1. Diligent claims 100% data integrity.

Built for enterprise data centers, ProtecTIER scales to address 1PB of physical storage, which is comparable to 25PB of data. It can reach sustained throughput of 200MBps. The platform is priced between $40,000 and $190,000, depending on the configuration.

This article was originally published on July 06, 2005