All information on the network is in bitstransmitA bit represents a 0 or 1.
Every 8 bits constitute onebyte（byte）。byteWhat is the concept?An English letter occupies one byte, that is, 8 bits, and a Chinese character occupies two bytes.The general digit is abbreviated as the lowercase letter "b",byteThe abbreviation is capital letter "B".
Design of storage capacity
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According to the requirements, the monitoring system of Fujian University of Technology adopts a centralized storage solution.The specific design is to deploy H3C EX1000S IPSAN storage server in the monitoring centercameraThe images of are transmitted to the monitoring center through the monitoring private network and stored on the IPSAN server.After the completion of the monitoring platform, it is also necessary to design different bitstreams according to the storage requirements: CIF: the image resolution is 352 × 288 D1; the image resolution is 720 × 576. CIF mode: 512K is used for storage per second for each channel. We refer to 512K storage system, which requires a total storage capacity of 160 cameras to store for 30 days;(Calculation formula: storage capacity (GB)=(bitstream/1024/1024/8) × CBR influence coefficient × 60 seconds × 60 minutes × 24 hours × days) Calculate the image storage capacity with 512K single channel video image bitstream.Hourly capacity=3600 seconds × (512/1024/1024/8) × 1.10=0.242G/hour, 24 hours a day, 24 hours a day, 24 hours a day, 24 hours a day for each image=24 Hour × 0.242GB/Hour=5.801GB/day, monthly capacity=30 days × 5.801GB/day=174.03GB, 160 cameras, 30 days storage capacity=160 × 174.03GB=27844.8GB=27.8TB, Full D1 mode: 2M is used to store each channel per second,We refer to the 2M storage system, which requires 14 cameras to store for 30 days;(Calculation formula: storage capacity (GB)=(code stream/1024/1024/8) × CBR influence coefficient × 60 seconds × 60 minutes × 24 hours × days) Calculate the image storage capacity with 1M single channel video image code stream, video image resolution of D1 720 * 576 PAL 25 frames.Hourly capacity=3600 seconds × (2048/1024/1024/1024/8) × 1.10=0.967G/hour, 24 hours a day for each image=24 Hour × 0.967GB/Hour=23.203GB/day, monthly capacity=30 days * 23.203GB/day=696.09GB, 14 cameras, 30 days storage capacity=14 × 696.09GB=9745.26GB=9.75TB[1]
Calculation of storage capacity
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Every 1000byteIt is called 1KB. Note that the "thousand" here is not 1000 in our usual sense, but 1024.That is, 1KB=1024B.However, if strict calculation is not required, it can be ignored that 1K is 1000.4) Every 1024 KB is 1MB (similarly, K here refers to 1024), that is, 1MB=1024KB=1024 × 1024B=1048576B, which is an accurate calculation.If the requirements are not precise, it can also be considered that 1MB=1000KB=1000000B
In addition, it should be noted that the storage product manufacturer will directly calculate the product capacity in the calculation mode of 1GB=1000MB, 1MB=1000KB, and 1KB=1000B, which is the main reason why the capacity of the purchased storage device cannot reach the nominal capacity (for example, the 320G hard disk is only about 300G)
Every 1024MB is 1GB, that is, 1GB=1024MB. As for how much is equal tobyte, do it yourself.We have found out what people often hearfloppy disk1.44MB, 650MB for a CD and 120GB for a hard disk.For example, if we save a novel with 100000 Chinese characters todiskHow much space does it need?100000 Chinese characters=200000B=200000B ÷ 1024 ≈ 195.3KB ≈ 195.3KB ÷ 1024 ≈ 0.19MB
Hard diskCalculation: The actual capacity of 750GB SATA is 667 (698.5) GB (the less part is used for the operating system);CBR influence coefficient: refers to the influence coefficient of CBR (constant bit stream) positive error on storage capacity.The storage device is arranged in RAID5+1 mode, and each storage needs to consume 2 hard disks. If the hard disk of IPSAN is 500GB, the effective storage capacity of each storage device is 6.316TB;If the hard disk of the IPSAN is 750GB, the effective storage capacity of each set is 9.119TB, and the relationship between the storage mode and the number of hard disks is as follows: Mode 1: deploy JBOD disks, use 750G hard disks (effective capacity 667GB), and the total capacity of 16 effective disks of a single machine is 10.672TB. Regardless of the reliability of the storage data, it is the most economic mode.Mode 2: RAID5 is deployed without hot spare disks. 750G hard disk (effective capacity 667GB) is used. The total capacity of 15 effective drawers in a single machine is 9.771TB. Regardless of the impact of RAID5 reconstruction on storage performance, this is the most economical mode.Mode 3: RAID5 is deployed and a hot spare disk is configured. 750G hard disk (effective capacity 667GB) is used. The total capacity of 14 effective disks in a single machine is 9.119TB. The impact of RAID5 reconstruction on storage performance is not considered (it is allowed to damage another hard disk in a short time after a hard disk is damaged).The required storage capacity can be calculated according to the number of monitoring points in each distribution area.(The scheme stores data) In the scheme, we can add storage devices at any time according to the needs of IP SAN storage, and carry out unified management.[1]
Introduction to Unit Conversion
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With the increase of the amount of stored information, there is a larger unit that represents the storage capacity unitbyte(GB, gigabyte) Higher:Terabyte(TB, terabyte), PB (Petabyte), EB (Exabyte), ZB (Zettabyte) and YB（yottabyte）Among them, 1PB=1024TB, 1EB=1024PB, 1ZB=1024EB, 1YB=1024ZB.So, how big is the capacity of these units?Let's see: Ki1obyte (KB)=1024B is equivalent to the content of a short story.
Megabyte (MB)=1024KB is equivalent to the text content of a short story.
Gigabyte (GB)=1024MB, equivalent toBeethovenThe content of the score of the fifth movement symphony.
Terabyte (TB)=1024GB, equivalent to all theX-rayPicture information volume.
Petabyte (PB)=1024TB, equivalent to 50% of American academic researchlibraryCollection information content.
Exabyte (EB)=1024PB；5EB is equivalent to the words spoken by people all over the world.
Zettabyte (ZB)=1024EB is like the total amount of sand on beaches all over the world.
Yottabyte (YB)=1024ZB is equivalent to 7000 bitshuman beingsIntracorporealMicrocellthe sum.
CUoM
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Storage capacity refers to the maximum amount of data that can be stored by the portable storage productcruxParameters of.Generally, the capacity of a USB flash disk is 1GB, 2GB, 4GB, 8GB, 16GB, 32GB, 64GB, and some products with higher capacity, but the price is beyond the user's acceptance.Among them, 1GB~2GB portable storage has been basically eliminated from the market;The 4GB~16GB products are the mainstream in the market, the price is acceptable to ordinary users, and they are also the capacity type with the most types of products launched by manufacturers;For products above 32GB, because of the high price, there are fewer users and fewer product categories.
Disk storage capacity
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As mentioned above, a disk usually adopts three levelsAddressing, therefore,Disk storageThe storage capacity of can be calculated with the following formula:
Storage capacity C=cylindrical surface（Track）Number T x Number of disk faces (heads) H xsector numberS
It should be noted that the storage capacity here refers toDisk storageThe amount of effective data that can be saved and many other information recorded on the disk are not included in the storage capacity.
Some people may have noticed that the newly purchasedHard disk, gridFormalizationThe storage capacity displayed later does not match the actual nominal storage capacity on the disk.The main reason is that the nominal capacity on the disk is given in decimal system, while the storage capacity inside the computer is actually expressed in binary system.For example, 1KB=1024B, 1MB=1048 576B, etcDisk storageThe error between the nominal capacity of the disk and the actual displayed capacity is approximately 5%. If it is expressed in GB, the error is 7.4%. If it is expressed in TB, the error is as high as 10%.
Database avoids waste of storage capacity
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One of the manifestations of a large waste of database storage capacity is data redundancy, which means that a field repeatedly appears in multiple tables.For example, if each customer's purchase information records the customer's own information, such data redundancy may cause inconsistency, because the customer's own information may be different.Data redundancy will lead to data anomaly and damage, which should be avoided in general design.Database normalization prevents redundancy and does not waste storage capacity.Proper use of foreign keys can minimize data redundancy and exceptions.However, if efficiency and convenience are considered, sometimes redundant data will be designed without considering the risk of data destruction.[1-2]
