Video surveillance continues to have an insatiable appetite for storage as surveillance systems increase in camera counts, megapixel resolutions and longer retention times.
Fortunately, disk drive space continues to increase to amazing capacities. Many storage vendors are already incorporating 2 Terabyte (TB) disk drives with more vendors to start by summer of 2009. Seagate Technologies Inc., Scotts Valley, Calif., is one provider of storage solutions and hard disk drives who recently launched a 2 TB enterprise-class disk drive as part of its line of Constellation™ All-Star Enterprise hard drives.
The disk-drive capacity trend follows “Kryder’s Law,” a corollary to the popular Moore’s law. Intel co-founder Gordon Moore observed that the power and memory of computer semiconductors doubles every 18 months while Seagate’s Mark Kryder recognized the similar rate of progression in disk drive storage and density.
Still, bigger disk drives are only part of the solution. As the storage demands increase, so do the requirements for fault tolerance, cost effectiveness and management simplicity. These requirements must be met with storage systems.
Most digital video systems have traditionally used direct attached storage (DAS) for video recording. DVR’s, NVR’s and video management servers rely on disks that are directly attached to the host through serial attached Small Computer System Interface (SCSI) connections. The disks can be packaged internally or externally to the host and can be arranged in Redundant Array or Inexpensive Disk (RAID) configurations to provide fault tolerance and survivability from a disk failure. While DAS systems are reliable, they limit the physical proximity of the storage with the video recorder and typically don’t allow storage to be shared across multiple recorders.
An evolving option to DAS is an architecture that leverages IP networks to share storage with multiple NVRs. Called IP Network Attached Storage (NAS) or IP Storage Area Network (SAN) systems, video is transported from the recorder system to the storage array using iSCSI protocol - or SCSI implemented over IP.
Providing the solution
One storage solutions provider, which also won the “Best in Show” award from the 2009 ISC West Show held in Las Vegas in April is Pivot3, Houston, Texas, provider of RAIGE™ and High-Definition Storage™. Pivot3 optimized its RAIGE Array solution, which uses iSCSI, to meet the demanding requirements of video surveillance systems and IP camera environments. The RAIGE Array system provides from 12 to 96 TB of shared storage across multiple databank appliances that provide up to 12 disks in a RAID configuration. The RAIGE software allows the array of databanks to be easily grouped into virtual storage volumes that can be allocated to NVR’s and other recording hosts.
An additional benefit of the Pivot3 system is a new Serverless Computing™ line that runs video management software directly on the Pivot3 RAIGE Array. Popular video management and NVR software applications from Genetec, Milestone, OnSSI and others can be hosted directly on the storage system to eliminate the cost and footprint of dedicated servers for video management.
The Pivot3 Serverless solution has been installed in critical infrastructure systems such as airports and casinos. One major U.S. airport originally specified DAS for the airport’s new 900 camera IP surveillance system, however, the Pivot3 system was ultimately selected for the project. According to the manager responsible for the airport’s video surveillance system, the Pivot3 Serverless approach provided cost, power and footprint efficiencies over a traditional DAS system.
As storage vendors continue to innovate and as long as Kryder’s Law continues to apply to disk drive capacity, we should expect storage systems to continue to grow with video’s increasing demand for storage, reliability and flexibility.
Tom Galvin of NetVideo Consulting is a network video specialist. His Web site is.