The suit, filed last month in the US District Court in the Northern District of California, alleges that Riverbed infringed on US Patent 5990810, "Method for partitioning a block of data into subblocks and for storing and communicating such subblocks," which was granted to RockSoft in 1999. RockSoft was subsequently acquired by ADIC, a company that was acquired by Quantum in 2006.
Quantum's lawsuit against Riverbed seeks an injunction from further infringement, damages and attorney's fees.
The lawsuit echoes a dispute Quantum had earlier this year with Data Domain, a data de-duplication vendor. As a result of that dispute, Quantum and Data Domain signed a cross-licensing agreement and Quantum received 390,000 shares of Data Domain stock. The two companies also signed a deal to not pursue additional lawsuits.
Quantum's de-duplication technology employs either in-line or post-processing capability. The manner in which de-duplication occurs has been a matter of hot debate in the last year. Data Domain uses in-line processing.