After the three hard disks are built into RAID5, which hard disk is installed in the system

The raid5 system is to combine 2 hard disks into a large hard disk, but the capacity is only equivalent to the total capacity of 2 disks, each hard disk has a part of the content, and each hard disk has 1 3 capacity is used as a "backup", that is, for recovery, the total redundant space of the three disks is just equivalent to a hard disk, and the available space of three hard disks is just equivalent to 2 hard disks, which is one of the characteristics of the RAID5 system. Similarly, the damage of any hard drive can be "rebuilt" with backup data, but the failure of two hard drives at the same time cannot be rebuilt.

After the RAID is built, it needs to be partitioned, just like the operation of a single hard disk, the system is only stored in a certain partition, no matter which partition, it is a part of the RAID storage space, of course, it is evenly distributed on the 3 hard disks.

RAID is a set of disk space that is used by synthesizing a disk into a disk according to a specific algorithm.

Taking RAID 5 as an example, each disk is striped, and the XOR operation value of the data and check value stored in each group of stripes is zero, and after the three disks form RAID5, a virtual disk with the capacity of two disks is obtained, and the virtual disk is partitioned and used.

Therefore, the system is actually distributed on these 3 disks according to the size of the strips.

Assemble a raid

The same model and capacity are required.

Although there are 2 pieces of 80g

But the interface is not the same.

Nor can it be formed.

.Assemble a raid

Theoretical performance doubled.

It is generally faster than a single hard drive.

RAID-6 requires a minimum of 4 hard drives. RAID-6 is a RAID level that increases the check information from one to two on the basis of RAID-5.

The storage mechanism of RAID5 is to store two pieces of data, one to store the other two hard disks, the rough transaction verification results, just like the simplest math problem, 1+2=3, when you are missing any of these numbers, you can find the third number by reverse inference. After the establishment of raid5, if one hard disk is broken, the third one can be calculated from the data of the other two hard disks, so at least 3 disks are required.

The first rock is RAID 5 is made by XOR effect: 1+2 3 If one of the digits is missing, can the equation be true, where 1 and 2 are the data, 3 is the check code, and the + sign is the calculation format, if 2 of them is lost, the array card can "calculate the data of 2" through 3-1=2, so when RAID 5 has a problem with one of the hard disks, although the system can run, but the speed will be very slow.

Answer]: CRAID adopts the N+1 mode, that is, if there are a total of N+1 spring digging portable disks, the capacity of N disks will be used to store the data and verify the information of the capacity of 1 disk.

Therefore, only 160T is used to store data, and 80T is used to store verification information, so the real capacity that can be used is 160T.

Answer]: The utilization rate of craid5 is 2 3Therefore, 300*3*2 3=600g is used