SAN (Storage Area Network) is high-performance storage presented as raw block devices over a dedicated storage network, typically Fibre Channel or iSCSI. Unlike a NAS, which serves files over the ordinary LAN, a SAN gives servers what looks like a local disk over a separate, fast fabric, with the throughput and low latency that heavy, continuous workloads need. It is the enterprise choice for large-scale live recording where many cameras write at once.
Its strength is sustained write performance and scale. Because it is block-level over a dedicated network, a SAN can absorb the relentless parallel write stream of hundreds or thousands of cameras without the protocol overhead that throttles file-level storage, and it centralises storage so multiple recording servers share a large, managed, resilient pool. This suits big deployments — city systems, large campuses, data-centre-grade VMS — where capacity and throughput both have to be high and manageable.
The pitfalls are cost and complexity. A SAN with its dedicated fabric, switches, and management is significantly more expensive and more specialised to run than NAS or direct-attached disks, so it is overkill for small or moderate systems where simpler storage would record the same cameras for far less. The sound approach matches storage class to load: direct-attached or NAS for smaller and archival needs, SAN reserved for high-density live recording that genuinely needs its throughput — and, as always, sized for sustained write plus RAID overhead, with redundancy, not just headline capacity.
The handbook · 7 volumes
Fora Soft Video Engineering Handbook
A SAN becomes the answer when recording servers can no longer absorb the combined write load of their cameras on local disks. Our seven-volume handbook covers the full video stack, and for SAN planning start with Volume 1, which covers bitrate, compression efficiency and codec choice, which determine the sustained write throughput your storage area network must deliver. Written by Nikolay Sapunov, CEO at Fora Soft.
Outgrowing local disks and weighing a SAN for surveillance recording?
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