RAID implementation

Implement soft raid

1. Fdisk t fd / / modify disk partition type fd

2. Create a raid device

Create a RAID5,5 block hard disk 4 blocks do RAID,1 block do idle hard disk (replace the hard disk)

Mdadm-C / dev/md0-a yes-l 5-n 4-x1 / dev/sd {bmeme creco dje Ji f}

-n #: use # block devices to create this RAID

-l #: indicates the level of RAID to be created

-a {yes | no}: automatically creates the device file for the target RAID device

-c CHUNK_SIZE: indicates the block size

-x #: indicates the number of free disks

Mdadm-D / dev/md0

-D: display the details of the raid letter

Cat / proc/mdstat / / observe the status of md:

3. Mkfs.ext4 / dev/md0 / / format raid devices

4 、 vim / etc/fstab

UUID= "b92ddd51-c555-4948-b1d5-8563b697a2f1" / mnt/raid ext4 defaults 0 0

5. Mdadm-Ds / dev/md0 > / etc/mdadm.conf generate configuration file

Mdadm-S / dev/md0 stop raid

Mdadm-A / dev/md0 starts raid

Out of service: mdadm-S / dev/md0

Activation: mdadm-A-s / dev/md0 activation

Forced startup: mdadm-R / dev/md0

6. Testing

Mdadm / dev/md0-f / dev/sdf1 simulated damage

Mdadm / dev/md0-r / dev/sdf1 Delete member

Mdadm / dev/md0-a / dev/sdf1 increased

Mdadm-G / dev/md0-n 6-a / dev/sdd4 add members

Note: if prompted by mdadm: Failed to initiate reshape! Indicates that the disk expansion (reshape) function does not support reducing the number of devices. Centos7 will have such an error.

7. Delete raid

Umount / mnt/raid

Mdadm-S / dev/md0 stop raid

Rm-f / etc/mdadm.conf

Vi / etc/fstab

Fdisk / dev/sda

Mdadm-- zero-superblock / dev/sdd1 / / Delete raid information