Direct to Storage TutorialBy: John Honovich, Published on Aug 19, 2012
Edge storage is hot. While attention centers on SD cards, that is not the only way to eliminate VMS servers. Another powerful tool in recording 'direct to storage' is to connect IP cameras to NAS appliances without any VMS server in between. In this note, we explain how this works, contrasting it to 'pure' edge storage and see where 'direct to storage' will fit in the marketplace.
For background, read our tutorial on Edge Storage and using SD cards.
Benefits Compared to SD Cards
Typically cameras that support recording to SD cards on-board also support recording to a NAS (e.g., Axis, Mobotix, March). However, two big benefits exis in recording direct to NAS:
- No storage size limitations. Unlike SD cards, NAS appliances can easily support 10TB+ storage. This overcomes the cost and duration limitations of SD cards
- More cost effective: NASes, unlike SD cards, tend to be quite inexpensive on a per GB basis.
Drawbacks Compared to SD Cards
However, using NASes has a few drawbacks for certain applications:
- More complex to setup: While setting up a NAS is not very hard, if you only have a few cameras, it is easier to pop in an SD card in each camera than to setup and connect cameras to a NAS.
- More costly for small systems: Even a 'cheap' NAS will cost ~$200 without hard drives. If you only have a few cameras, it is likely cheaper to use SD cards.
- Beware of resource constraints: Many lower end NASes are not designed to handle continuousing recording of surveillance video. Be sure the NAS you specify can handle the camera load.
Overall Direct to NAS Positioning
Unlike SD card storage, direct to NAS recording is overall better positioned for larger, more conventional applications. For those who want to eliminate VMS servers, NASes are best positioned for larger camera counts or higher storage durations (multi-month, full frame rate, etc.). Additionally, just like traditional VMS recorder, a stable network with sufficient bandwidth will be needed as the video must be sent in real time from the IP camera to the NAS appliance.
Key Barrier - Camera Client Sophistication
Larger camera count, higher storage demanding applications typically want their VMS to have greater functionality. Minimally, to support the higher number of cameras but also to support features like multi-camera vendor interoperability, multi-camera simultaneous searching, to name two very fundamental ones.
However, it will be interesting if camera vendors add such functionalities in as doing so would put them in to further direct conflict with VMS vendors. While a company like Mobotix seems not to care, most traditional IP camera vendors are likely more reluctant.
The Axis Example - Real Constraints
Axis Camera Companion (ACC) shows the key constraints in practice. While Axis cameras can record directly to NAS appliances while using ACC, ACC has a hard limit of 16 cameras, only supports Axis cameras and only one camera at a time playback. Today, the direct to NAS option only helps with extended storage or perhaps recording closer to the max of 16 cameras. However, it fails on many levels for bigger systems even if the NAS recording option could handle dozens of Axis cameras.
What Will Happen
As camera manufacturers add in edge storage management, support for direct to NAS recording are likely. To that end, minimally it should be an advanced option for smaller systems that want more storage or less expensive storage. However, until and less camera manufacturers are willing to beef up their VMS client offerings, the full potential of direct to storage recording will not be achieved.