Building a functional and secure surveillance system requires a clear and detailed understanding of storage solutions and the network.
Storage options depend hugely on what type of cameras are used as well as FPS, resolution and codec. The best way to work out storage is to use the camera manufacturer storage calculator as each camera manufacturer uses codec differently.
Local storage – Using local storage means you will not use up network bandwidth and it can also give a faster throughput of data as there are less bottlenecks between the CPU and the storage. However, there is a limit to the amount of storage we can add to the server and access to the data is lost if the server breaks down.
NAS storage – Using network storage adds a level of robustness as there is access to the data even if the server breaks down. However, putting extra strain on the network can slow down the amount of data that can be written to disk as the network might not be able to handle the large amount of data. Moreover, networked storage allows multiple users in a shared network to have access to the same information. Depending on the type of operating system, access to information or individual networked storage drives can be restricted by user, user group, IP-address, MAC-address or with software-specific means.
Combining the two storage options is often the most robust solution as it will effectively mean you are backing up your data and also allows you to maintain backups with important data for longer.
The picture below gives an example of using networked storage with VMS and with a hybrid fibre channel switch connecting to a TCP/IP network.
Edge recording – Automated Edge Recording allows the recording and saving of data on the SD card installed on the camera; in case of a network blackout or recorder malfunctions. When the connection is restored, the recorded footage are automatically transferred on the recorder. The process starts automatically and runs on the background. With a 16GB SD memory installed, a single SD card can store up to 3 days recorded data, depending on the frame rate and image quality – enough to cover a large-scale network blackout or server breakdown.
To learn more about network storage have a look at our white paper here.
How to keep your storage safe?
To protect your data and maximise recording continuity, Mirasys VMS supports a multi-disk recording option. When using RAID arrays, RAID 6 or RAID 10 are the general recommendations. Whenever any kind of RAID array is used, it is strongly recommended to use only server level hard disks that have RAID optimised firmware. The cost is usually higher than hard disks for home use, but the benefits are clear: Non-RAID optimised desktop hard disks tend to frequently drop out of RAID arrays. Server level hard disks have a more robust build and steadier quality. Please note that due to RAID rebuild time after a failed disk we recommend using disks no bigger than 4 TB.
Adding storage space
If additional storage space is required, you can add new hard disks or map a network drive for data storage. Please note that only local hard disks or one network drive can be used for data storage; local hard disks and a network drive cannot be used simultaneously. When adding a local hard disk to the recorder, make sure that it has the same capacity of the other disks, as the SDD feature of the recorder reserves an equal quantity of space on each disk, based on the lowest free storage space on any of the hard disks. For example, if there are two 1TB disks and one 2TB disk, the system reserves all but 990GB (leaving 10GB free on the 1TB disks and 1010GB free on the 2TB disk).
Instructions for adding storage space through local and network HDD’s can be found in Mirasys VMS manuals, included in your DVMS setup package.