Multipath call failed exit. This warning occurs in the Compute log if you do not have the optional multipath-tools package installed on the compute node. This is an optional package and the volume attachment does work without the multipath tools installed. If the multipath-tools package is installed on the compute node, it is used to perform the volume attachment. The IDs in your message are unique to your system. WARNING nova.storage.linuxscsi [req-cac861e3-8b29-4143-8f1b-705d0084e571 admin admin|req-cac861e3-8b29-4143-8f1b-705d0084e571 admin admin] Multipath call failed exit (96)

Run the following command on the compute node to install the multipath-tools packages. $ sudo apt-get install multipath-tools