RAID is a combination of multiple disks in a specified way
to provide higher performance and security than a single disk
RAID implementation:
External disk array
Built-in RAID: Mainboard integrated RAID controller
Software RAID: Use software to simulate RAID
级别：
RAID-0
RAID-1
…
RAID-5
RAID-6
RAID-10
RAID-01
RAID-50
RAID-60
RAID-0:
Features:
Improved read and write performance.
Available space: N single disk size
(for example: single disk 2T, two disks=2 2T=4T, four disks 4*2T=8T)
No fault tolerance, at
least two disks
RAID1-mirroring
Features:
read and write performance: read performance improved, write performance decreased
Available space: N single disk size/2
(for example: total capacity of 2 2T disks 2 2T/2=2T, four 4T disks: 4*4T/2 =8T)
has fault tolerance.
Minimum number of disks: 2
RAID5
Features:
Read and write performance: Improved read and write performance.
Available space: (N-1)*single disk size
(for example: total capacity of 4 4T disks (4-1) 4T=12T, 8 10T disks: 7 10T= 70T)
Fault tolerance: 1 hard disk
Minimum number of disks: 3
RAID6
Features:
Read and write performance: Improved read and write performance.
Available space: (N-2)*Single disk size
(for example: 4 12T disks with a total capacity of 24T, 8 12T disks with 72T)
Fault tolerance: 2 disks with
minimum disk Number: 4
Mixed type
RAID10
Features:
Read and write performance: Improved read performance
Available space: N*single disk capacity/2
Fault tolerance: Each group of mirrors can break at most one piece.
Minimum disk: 4
RAID01
Features:
Reading and writing performance: Reading performance improvement
Available space: N*single disk capacity/2
Fault tolerance: At least one set of disks
Minimum disk: 4