Disable and Blacklist all devices in dm multipathing on RHEL7

If you want to use any other third party multipathing software apart from DM (Linux native multipathing) then to disable DM follow below steps:

1. Blacklist all devices in /etc/multipath.conf. Edit /etc/multipath.conf so that it contains only the following lines:

 blacklist {
devnode "*"
}
2. Ensure dm-multipath does not start automatically at boot.

 # systemctl disable multipathd.service

 # systemctl list-unit-files | grep multipath
 multipathd.service                          disabled
3. Recreate initramfs so that dm-multipath is excluded from initramfs.

 # dracut /boot/initramfs-wo-DM-$(uname -r).img $(uname -r)

 Take a backup of existing /boot/initramfs-$(uname –r).img file and rename the above created initrmafs file to the name of orginal initramfs file.
4. Reboot the host with the new initramfs image and ensure dm-multipath does not have

 5. To check if any devices are configured

 # multipath -ll --- should not return any dm devices

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