[Management] hardware RAID arrays

RAID definitions

The RAID (Redundant the Array of Inexpensive / work of the Independent Disks) refers to a set of disk drives linked as a logical disk drive.

advantage

1. High transfer rate : In the section RAID mode, multiple disks can transmit data at the same time;
2. Safe : Some RAID modes are data recovery function, when one of the RAID disk drive failure, data corruption can be restored by RAID disk to other disks.

RAID Category

RAID0 (no no redundancy check array)

Features:

1. No fault tolerance;
2. The fastest read and write;
3. Any damage will cause the entire RAID disk failure;
4. It requires at least two disks.

RAID1 (mirroring disk array)

Features:

1. Each disk corresponds to a mirror disk;
2. Maximum safety;
3. Only half the disk space is used to store data;
4. Requires at least two disks;

RAID0+1

Features:

1. Data is distributed over a plurality of disks;
2. Each disk has a mirror; allows up to a disk failure;
3. Fast reading and writing skills;
4. Requires at least four disks;

A RAID5 (no independent check parity disk array)

Features:

1. No independent check disk, quick check calculation dispersed in all RAID disks for each band;
2. The effectiveness of more integrated than the above-mentioned three kinds;
3. Requires at least three disks;
4. Disk volume increase will lead to an increased risk;

JBOD（Just Bundle Of Disks）

Features:

1. Simple disk bundle;
2. Disk series, filled sequentially one by one;

Matrix RAID

Features:

1. On 2 disks while achieving RAID0 and RAID1, disk space as part RAID0 / RAID1, the remaining space as RAID1 / RAID0;

Size Example