Redundant array of Linux disks

RAID to prevent physical damage to the hard disk and increase the throughput of the storage device, RAID common combinations are 0, 1, 5, and 10RAID0: a minimum of two hard drives, can effectively improve the performance and throughput of the hard disk, but no data redundancy and error-repair ability to connect multiple hard disks in a hardware or software way together , becomes a large volume set, writes the data sequentially to each hard disk, so the performance can greatly improve, but if any one piece of hard disk failure then the entire system data will be destroyed! RAID1: Requires at least two hard drives, can effectively improve the security and repair of data, but the cost is high when the data is written to the hard disk will also be on another idle hard drive to generate image files, without compromising performance to maximize the reliability of data information, As long as there is a hard disk in a pair of mirrors can be used, then the data will not be lost, with good hard disk redundancy, but the disk utilization is only 50%RAID5: requires at least three hard drives, balancing performance, data security and storage costs per disk using "parity" Block to hold parity information for other hard disk data (not data on other hard drives) to secure data with parity information RAID10: requires at least four drives, both speed and security, but at a high cost inherited RAID0 's fast and RAID1 security, The combination of RAID1 and RAID0, four hard drives 22 to RAID1 form a redundant array, and two RAID1 to form a read-write array RAID0! High cost! Typically used to store data requiring speed and error control MDADM command:-a detection device name-n Specify number of devices-L specify RAID level-C Create-V display procedure-F analog Device damage-R Remove device-a add device-Q view summary information-D View details-s stop array [[ Email protected] dev]# mdadm-cv/dev/md0-n 5-l 10/dev/sdb/dev/sdc/dev/sdd/dev/sde# Create a RAID10 array with four hard disks, allowing a group of RAID1 to have a Failure disk without affecting using [[email protected] dev]# mdadm-cv/dev/md0-n 3-l 5-x 1/dev/sdb/dev/sdc/dev/sdd/dev/sde# Create RAID5 array, use three hard drives, left More than one as a backup disk, when one of them is automatically replaced when a fault occurs

　　

Redundant array of Linux disks