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Published: 12 Oct 2007
IP-based camera video surveillance systems are increasingly moving video storage off closed-circuit television (CCTV) and digital video recorders (DVRs) and onto network-attached disk storage. To address this shift, new video surveillance storage systems with high-availability, bandwidth and scalability characteristics are emerging; these new systems are using SATA disk drives, iSCSI connectivity and clustering software to meet video surveillance's particular storage requirements.
John Webster, principal IT advisor at Illuminata, Nashua, NH, observes that companies gain a huge advantage by digitally storing video surveillance footage. "People can fall asleep and miss actions when they review analog video," says Webster. "When video is stored digitally, you can do an awful lot of preprocessing that identifies periods of time when action is occurring."
Connexed Surveillance Service, Palo Alto, CA, is a video surveillance storage service provider that uses a software-as-a-service (SaaS) model to deliver video surveillance. Subscribers use Connexed-provided IP-based cameras and a video surveillance platform that captures and briefly stores video data at the client site before sending it across the Internet for final archiving at Connexed's data center.
Keeping up with video surveillance data that's coming in faster than he can store it on his low-cost primary system, as well as trying to find the time and money to backup all the data is overwhelming, says Rick Bentley, chairman and CEO at Connexed Surveillance Service. Connexed created its own clustered storage system using off-the-shelf servers and storage, but the maintenance and support didn't meet customers' desired levels of data availability.
"Even though it's video surveillance, customers still get cranky when you lose data," says Bentley.
To lower total cost of ownership and increase data availability, Connexed selected Pivot3's RAID Across Independent Gigabit Ethernet (RAIGE) storage cluster to attach to Connexed's data center servers. The cluster consists of server nodes called Databanks that run Pivot3's distributed RAID software and contain additional processing capacity, cache and storage for increased video capacity and throughput. Each attached server at Connexed's data center uses Pivot3's kernel-level driver, which provides direct parallel access to LUNs on Pivot3's Databanks and stripes data across them.
Pivot3 protects data using RAID 5 when only one or two Databanks are deployed, but its distributed RAID software automatically creates a Databank cluster across three or more Databanks so it can withstand the failure of a single Databank. As more Databanks are added, the Pivot3 distributed RAID software automatically redistributes and load-balances data across the multiple Databanks.
Other firms are also looking to meet the specific storage needs of video surveillance. For example, Intransa's StorStac storage system supports iSCSI-based video surveillance, but gives companies the flexibility to increase performance or capacity on a more granular level. Firms may add Intransa's Performance Controller Units (PCUs) when they require more performance or higher levels of failover, or the company's Storage Capacity Enclosures (SCEs) when more storage resources are needed.
Webster sees digitized video surveillance as almost certain to grow as it eliminates tape management and the out-of-space conditions that CCTV and DVRs can introduce. By placing it all in one digitized storage pool that's easily accessible, says Webster, "if you have a five-minute sequence of corporate video surveillance data that you need to locate, you now have all of that data at your fingertips."
--Jerome M. Wendt