Network Instruments has developed what it claims is the largest network data recorder available. The GigaStor SAS has a capacity of up to 288 terabytes, and was originally developed for a U.S. military customer which needed to store a month's worth of the traffic on its network, said Douglas Smith, the company's president and co-founder.

The device is a extension of NI's current GigaStor retrospective network analysis (RNA) line, and incorporates SAS or SATA disk arrays for its storage. RNA involves capturing all the packets and transactions traversing a network and storing them for later analysis or playback.

It can support E1, HSSI, DS3, and Fibre Channel networks as well, but Gigabit and 10G Ethernet are the main targets, Smith said. He added that NI developed its own 16-lane PCI Express card for 10G Ethernet, to ensure that GigaStor could capture data even at full-duplex line rate.

"Our capture card is at least twice as fast as competitive offerings. Most competitors' 10G NICs use only an eight-lane PCI Express adapter," he claimed.

"GigaStor SAS customers have so far been either government or financial organizations with extremely large storage and/or long-term data retention needs," he added.

"The larger storage needs are due to either high network volumes, or regulations that mandate and govern long-term data retention. Coupled with the trend to consolidate activities into larger data centers, customer demand for larger, scalable solutions will continue to increase."

If even more storage is needed, NI also offers a write-to-SAN option that stores the capture network data on a storage area network. However, Smith noted that with full-duplex 10G Ethernet, the bottleneck is more likely to be the speed of writing to storage, and said that here he'd recommend high-speed SATA arrays as being faster than either SAS or SAN.

The 10G-capable GigaStor costs £75,000 (AUD$160,000) for the head unit, plus some £22,500 for each 16 TB of storage. A Gigabit Ethernet model is cheaper, at £45,000 for the head unit, Smith said.