Mountain View-based flash-storage developer Violin Memory said Friday that it has acquired GridIron Systems, a developer of storage area network acceleration devices. Financial terms of the buy were not disclosed. Gridiron is venture backed, and was headed by Som Sikdar, who also formerly co-found Shomiti Systems (Finisar) and Force10 Networks. GridIron Systems was based in Sunnyvale. Violin Memory is backed by Toshiba, Juniper Networks, SAP Ventures, and Highland Capital.