Install dmadm
fdisk -l view disk information, 6 A 100GB disk, namely /dev/sdb, /dev/sdc, /dev/sdd, /dev/sde, /dev/sdf, /dev/sdg
Create raid5, two hot spare disks
-C create Raid
-v display process
-n specify Number of Raid Disks
-l Specify Raid level
-x Specify the number of hot spare disks
Use mdadm -D /dev/md0 to view Raid information, Raid is rebuilding
Use mdadm -D /dev/md0 to view Raid information in about 3 minutes, Raid initialization is complete
Format
Mount the partition
Simulate failure
/dev/sdg convert from hot spare disk rebuiding to raid disk