Several modes of disk array
: RAID0 RAID1 RAID5
RAID0
Advantages: The stored data is divided into two parts and stored on two hard disks respectively. At this time, the theoretical storage speed of the mobile hard disk is twice that of a single hard disk, and the actual capacity is equal to twice the capacity of the smaller one of the two hard disks. .
Disadvantage: If any hard disk fails, the data on the entire RAID will be unrecoverable.
Indicates that vdb1 and vdb2 are active, vdb3 can find that vdb1 and vdb3 are active when the standby
mdadm /dev/md0 -f /dev/vdb2 forcibly
monitors vdb2 for damage,
mdadm /dev/md0 -r /dev/ vdb2 remove vdb2
mdadm /dev/md0 -a /dev/vdb2 and add vdb2 to this device
Delete disk array
1, unmount umount /mnt
2, madm -S /dev/md0
3, fdisk /dev/vdb
Detailed explanation of mdadm command
-C create
-l level
-n number of devices
-a {yes|no} automatically create a device file for it
-c specify the data block size (chunk)
-x specify the number of free disks (hot spare disks), free The disk (hot spare disk) can be automatically replaced after the working disk is damaged