Skip to main content

Live Migration Failed, Multipathd Service Not Running on Destination Host

  • Updated

Problem

Instance live migration fails with below error in ostackhost.log of source host.

ERROR nova.compute.manager [-] [instance: "instance-id"] Pre live migration failed at "destination-host-uuid": RemoteError: Remote error: ProcessExecutionError Unexpected error while running command.
Command: multipathd show status
Exit code: 1
...
TRACE nova.compute.manager [instance: "instance-id"] Stderr: u'ux_socket_connect: Connection refused\n'

Environment

  • Platform9 Managed OpenStack - All Versions
  • multipathd
  • pf9-ostackhost

Cause

  • The pf9-ostackhost service on the source and the destination host is configured to use the multipath connection for volumes.
    # less /opt/pf9/etc/nova/conf.d/nova_override.conf
    ..
    volume_use_multipath = True
    ..
  • Once the live migration is initiated, a pre-live migration check is performed to confirm if the destination host is running the multipathd service.
  • If this pre-live migration check fails, the below command on the destination host will give the error mentioned in the problem section on source host. 
    $ multipathd show status
  • On the destination host, we can observe the error message with the live-migration request ID as below. 
    ERROR os_brick.initiator.linuxscsi [req-xxxxxxxxxxx user@domain service] multipathd is not running: exit code 1: ProcessExecutionError: Unexpected error while running command.
  • Check the status of multipathd service on the destination host. 
    $ systemctl status multipathd.service
  • This issue is most often observed if the multipathd service is not running on the destination host.

Resolution

  • Check multipath configuration in /etc/multipath.conf file on destination host.
  • If the configuration is correct, start the multipathd service if not running on the destination host. 
    $ systemctl start multipathd.service