1. Storage System Optimization

2. Introduction Storage Types-DAS/NAS/SAN The purposes of different RAID types. How to calculate the storage size for video recording?

3. Agenda The position of storage in the procedure of video surveillance system. Common types of storage. Fibre Channel and iSCSI in SAN. RAID Storage Size Calculation

4. The Procedure of Video Surveillance System Transmit Data Recording video Storage Capture Video Decompress Data for Playback Compress Data NVR Decompress Data for live View

5. Basic Storage NVR Hard Disk Store the recording video In this architecture, we call “Direct-attached storage” (DAS). It is simple to install and has high security. However, If the storage requirement is increased, it is difficult to be expanded more hard disk. It is not easy to share the stored video to other people.

6. Storage with Internet NVR Workstation Internet In this architecture, we call “Network-attached storage ” (NAS) It can expand to add other storage devices flexibly. Ease to share stored video data in storage device. However, Network bandwidth is unstable might cause the video lag. NVR Server Storage device Store the recording video Request the recording video to playback from server Storage device

7. Independent network of storage system Storage Device Switch Storage Device Switch NVR server SAN Internet NVR Workstation Store the recording video Request the recording video to playback from server Storage area network (SAN). Because storage devices are independent from servers, SAN increases the storage space usability and provide efficient sharing system. It provides high speed of connection in SAN system. Ex, Fibre Channel (Optical Fiber) and iSCSI (Ethernet) technologies.

8. Fibre Channel Fibre Channel means the connection between NVR server 、 switch and storage devices in SAN system use “Optical Fiber”. The cables and equipments are special for optical fiber. The maximum data rate of fibre channel is up to 1600 MByte/s. The maximum distance of optical fiber cable is up to 50 km. Storage Device Switch Storage Device Switch NVR server SAN Internet NVR Workstation Optical fiber Ethernet

9. iSCSI iSCSI is based on Ethernet network architecture and uses exclusive communication over IP networks in SAN system to achieve high speed connection. iSCSI also need specific equipment to support iSCSI protocol, including the Ethernet card of server/storage devices and the switch. In iSCSI needs to use the exclusive communication to define the transmitter (iSCSI initiator)and the receiver (iSCSI Target ) for server and storage devices at first to send information. Storage Device Switch Storage Device Switch NVR server iSCSI Card iSCSI Ethernet Switch Ethernet Transmitter Receiver

10. How to advance storage function? We want to Increase the speed of storage. Backup the storage data. RAID (Redundant Array of Independent Disks)

11. RAID RAID uses multiple independent disk drives to increase storage functions. The purposes of different RAID types are – Speed up the transmission of data storage. – Backup the storage data. – Recovery the storage data while one disk drive has damage situation.

12. Increase the speed of storage Data D Data C Data B Data A Data C Data A Data D Data B Disk 1 Disk 2 Storage It transmits the sequence sections of one data to two disks separately. Ex, data A to disk1, data B to disk2 and data C to disk1…etc. Thus, the speed of storage data shall be the half than normal type.

13. Data D Backup Data C Data D Data C Data B Data A Data B Data A Disk 1 Disk 2 Storage Data D Data C Data B Data A It transmits the same section of data to two disks synchronously. Ex: Data A to disk1 and disk2 in the same time. Data B to disk1 and disk2 in the same time. Disk 2 is the backup of disk1. While some data in disk1 have damage, we still can find data on disk2.

14. Data F Data E Recovery Data D Data C Data B Data A Data E Data C Data A Data F Data D Data B Disk 1Disk 2 Storage Encode (E, F) Encode (C,D) Encode(A, B) Encode(A, B) Disk 3 It transmits sequence sections of a data to two disks and also store the encoded data of transmitted sections to third disk. If disk 1 has error or damage situation, we can replace a new disk and use the encode data in third disk to recovery the original data in disk1. Data E Data C Data A

15. Storage Size Calculation

16. Storage size calculation Storage size (bytes) = bitrate * x Time (sec) / 8 ** * bitrate = video data size (bit)/sec ** bit  byte (8 bits = 1 bytes)

17. Storage size calculation Ex: If the 1 Mbps video from one camera has to be stored in NVR server for 5 days, how big storage space do I need? A: Time (sec)=5(day)x24(hour/day)x60(min/hour)x60(sec/min) = 432,000 (sec) Storage size= 1Mbps x 432,000 (sec) / 8 = 432,000M (bit) / 8 = 54,000M (byte) = 54G (byte)