Raid
RAID level: Only means that the disk is organized differently, with no contextual points:
0: Strip
Benefits: Performance Improvement: Read, write
Insufficient: No redundancy (fault tolerance) capability
Space utilization: NS
At least 2 plates required
1: Mirror
Performance: Write performance degradation, read performance improvement
Redundancy capability: Available
Space utilization: 1/2
At least 2 plates required
2
3
4: Check Code
5: Take turns as a calibration disc
Performance: Read and write are improved
Redundancy capability: Available
Space utilization: (n-1)/n*ns
At least 3 bucks.
6
0,1,5 used More
0+1: First strip, then mirror
Performance: Read and write promotion
Redundancy capability: Available
Space utilization: 1/2
At least 4 bucks.
1+0: Mirror First, then strip
Performance: Read and write promotion
Redundancy capability: Available
Space utilization: 1/2
At least 4 bucks.
5+0:
Performance: Read and write promotion
Redundancy capability: Available
Space utilization: (n-2)/n
At least 6 bucks.
JBOD: To combine multiple small discs into a single market
Performance: None
Redundancy capability: None
Space utilization: 100%
At least 2 bucks.
Logical raid:
/dev/md#
/dev/md1
/dev/md2
/dev/md3
Md:
Mdadm: Make any block device raid
Modal Commands:
To create a pattern:
-C
Dedicated options:
-L: Level
-N: Number of devices
-A {Yes|no}: whether to automatically create a device file for it
-c:chunk size, default 64KB
Management mode:
--add,--remove
mdadm/dev/md#--FAIL/DEV/SDA7: Simulation for damage
Monitor mode:
-F
Growth mode:
-G
Assembly mode:
-A
Stop array:
Mdadm-s/DEV/MD1
mdadm-d|--detail/dev/md#: viewing array # Details
Save the current RAID information to the configuration file and assemble it later:
mdadm-d--scan >/etc/mdadm.conf
Watch: Periodically executes a command and displays the results in full-screen mode
-N #: Specify the period length # seconds, default is 2s
Syntax: watch-n # ' command '
Md:multi Device
Dm:device Mapper
Logical devices
Raid,lvm2
Introduction to Linux raid
