Introduction to disk arrays (RAID-0,RAID-1,RAID-5)

RAID, or Redundantarrays of Lnexpensive Disks (RAID), is a fault-tolerant, inexpensive disk array.

First, RAID-0

Isometric mode-stripe for best performance

This model is best if it is made up of two types of disks with the same capacity. This mode of RAID will cut the disk into equal chunks, and when a file is written to raid, the file will be cut according to the size of the block and then placed in each disk. Since each disk is interleaved with data, data is placed on each disk in equal amounts when data is written to the raid.

Second, RAID-1

Image mode-mirror, full backup

This mode also requires two types of disks with the same capacity. If a copy of the data is written, it will be written to two disks, and each disk will be saved in one copy.

Advantage: The backup of the data, because half of the disk capacity is used in the backup, so the total capacity will be half of all disk capacity.

Third, RAID-5

Balance of performance and data backup considerations

At least three or more disks are required to make up this type of disk array. Write similar to RAID-0, a bit more than the same check data, this data will record the backup data of other disks for rescue when the disk is damaged. Because of the same check code, the total capacity of the RAID5 is reduced by a chunk of the overall disk count.

RAID5 only supports the damage of a piece of disk by default. Spare disk preparation capabilities.

is one or more disks not included in the original disk array level, this disk is not used by the disk, when there is any disk damage to the disk array, then this piece of spare disk will be actively pulled into the RAID array, and the broken hard drive out of the disk array, and then immediately rebuilt the data system, So that can be forever healthy.

In addition, RAID 0+1, or RAID 1+0

Introduction to disk arrays (RAID-0,RAID-1,RAID-5)