If RAID5 is damaged in the Centos system, the data is automatically switched to the backup disk.

RAID5 + disk quota, 1 disk, simulation of 5 disks in five partitions, four of which are made into RAID 5 partitions, the remaining one as a redundant disk, mounted to the/data1 directory, when one disk is damaged, the redundant disk status automatically changes to active. (You can also mount five disks, with the same effect .) For details about how to create a disk, see

Http://dreamfire.blog.51cto.com/418026/1084729

Note: In a real production environment, RAID volumes are implemented through real disks, and the software implementation is not stable enough. We do not recommend that you use RAID volumes. This experiment demonstrates how RAID5 works.

Run the mdadm command to create the disk array RAID 5 (Note: RAID should have at least three disks. Here we simulate four disks and one hot backup)

-C: Create a RAID block device after the RAID block device name-l 5: specify the number of RAID 5-n 4 used to create a RAID 5 disk, that is, the number of active disks. raid5 has at least three disks, -x 1 Number of backup disks,

View the disk array creation, it can be seen that the sdb5-sdb8 is RAID5, sdb9 is hot standby.

Format the RAID5 md0 disk array.

Use mount

Simulate a disk that is damaged by sdb8.

We can see that sdb8 is changed to faulty space, and hot standby sdb9 quickly replaces sdb8 and becomes active.

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