CentOS installation multi-path, and how to deal with the problem that the newly added disk cannot be formatted after installation

1. Install multipath
 
yum -y install device-mapper-multipath

systemctl enable multipathd.service

vi /etc/multipath.conf

blacklist {
    devnode "^sda"
}
defaults {
    user_friendly_names yes
    path_grouping_policy multibus
    failback immediate
    no_path_retry fail
}

systemctl start multipathd.service

multipath -ll will output mpath*** size*** and other information (Note: If the output is empty, you can restart and take a look. If it does not work after restarting, it may be that the vmware configuration does not add the disk.EnableUUID=TRUE option, or the machine only has sda disk.)

The lsblk command outputs an additional mpath* partition on disks other than the sda ​​disk.

2. Solution to error when formatting disk in multi-path environment

错误描述：/dev/*** is apparently in use by the system; will not make a filesystem here!

Solution: vi /etc/multipath.conf Add the device path that needs to be formatted in the blacklist item, and then reload the multipathd service.

3. Example