RAID disk array

Catalog

RAID Disk display

raid 0

raid 0 Characteristics

raid 1 Characteristics

raid 5

raid 5 Characteristics

raid 6

raid 1+0( First make a mirror image , And then make a strip )

raid 1+0 Characteristics

experiment

---

RAID Disk display

yes Redundant Array ofIndependent Disks Abbreviation , Chinese abbreviation is Independent redundant disk array

frequently-used RAID Level
RAID0,RAID1,RAID5,RAID6,RAID1+0 etc.

raid 0

raid 0 Divide data continuously in bits or bytes , Read in parallel / Write on multiple disks , Therefore, it has high data transmission rate , But it has no data redundancy
raid 0 Just to improve the performance , There is no guarantee for the reliability of the data , And a disk failure will affect all data
raid 0 It can't be used in the situation with high data security requirements

raid 0 Characteristics

You need at least two disks
Distributed data strip
There is no redundant , Best performance （ Do not store images 、 Check information ）
It can't be used in the situation of high data security

raid 1 Characteristics

You need at least two disks
Provide data redundancy （ Provide backup ）
Good performance

raid 5

N(N≥3) The disks form an array , A data generation N-1 A strip , There is also a verification data , common N The data is in N Cycle balanced storage on the block disk
N Read and write at the same time , High reading performance , But because of the problem of checking mechanism , Write performance is relatively low
（N-1）/N Disk utilization
High reliability , Allow one disk to break , It doesn't affect all the data

raid 5 Characteristics

least 3 Block disk
The data is striped
Redundancy with parity
Suitable for reading more and writing less , It's the best compromise between performance and data redundancy
 

raid 6

N（N≥4） The disks form an array ,（N-2）/N Disk utilization

And raid 5 comparison ,raid 6 A second independent parity information block is added

Two independent parity systems use different algorithms , Even if two disks fail at the same time, data usage will not be affected

be relative to raid 5 There are bigger ones “ Write loss ”, Therefore, the write performance is poor

raid 1+0( First make a mirror image , And then make a strip )

N ( even numbers ,N>=4). After two disks are mirrored , Then combine it into a raid 0
N/2 Disk utilization
N/2 All disks are written simultaneously ,N All disks are read at the same time
High performance , High reliability

raid 1+0 Characteristics

least 4 Block disk
According to the first raid 0 Divide into two groups , And then press raid1 Mode image
Take care of redundancy （ Provide mirrored storage ） And performance （ The data is striped ）
It is commonly used in practical application
 

experiment

First fdisk -l Check out adding to disk

 

  Divide the four fast disks into main partitions

  install mdadm（ Installed needs yum to update ）

 

  Create and view raid5

  View disk details

  Create a new directory , Mount after formatting

 

  Try to make a disk fail , See if the empty disk can replace the faulty disk

 

Create and view raid0

Divide the main area and mdadm Reference resources raid5