I am trying to live migrate an instance which is running from a cinder volume. The command completes without any errors, and I can't find any errors in logs on the controller, source host, or destination host. Dashboard/CLI (nova and openstack commands) same result.

The only thing I can find that is remotely suspicious is in nova-compute.log on the destination host:

WARNING os_brick.initiator.connectors.iscsi ... ISCSI volume not yet found at: [u'...']. Will rescan & retry.  Try number: 0.
WARNING nova.compute.manager ... Detaching volume from unknown instance
WARNING nova.virt.libvirt.driver ... During detach_volume, instance disappeared.

There are some messages in syslog that correspond with this, but I'm not certain if there is a problem or if this is normal behavior when the host attaches a new volume and re-scans the SCSI bus:

kernel: sd 11:0:0:0: Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatical
kernel: sd 11:0:0:3: [sdi] Unit Not Ready
kernel: sd 11:0:0:3: [sdi] Sense Key : Illegal Request [current]
kernel: sd 11:0:0:3: [sdi] Add. Sense: Logical unit not supported
kernel: sd 11:0:0:3: [sdi] Read Capacity(16) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
kernel: sd 11:0:0:3: [sdi] Sense Key : Illegal Request [current]
kernel: sd 11:0:0:3: [sdi] Add. Sense: Logical unit not supported
kernel: sd 11:0:0:3: [sdi] Read Capacity(10) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
kernel: sd 11:0:0:3: [sdi] Sense Key : Illegal Request [current]
kernel: sd 11:0:0:3: [sdi] Add. Sense: Logical unit not supported
kernel: scsi 11:0:0:1: Direct-Access     IBM      2145             0000 PQ: 0 ANSI: 6
kernel: scsi 11:0:0:1: alua: supports implicit TPGS
kernel: scsi 11:0:0:1: alua: port group 00 rel port 180
kernel: scsi 11:0:0:1: alua: rtpg failed with 8000002
kernel: scsi 11:0:0:1: alua: port group 00 state A non-preferred supports tolusna
kernel: scsi 11:0:0:1: alua: Attached
kernel: sd 11:0:0:1: Attached scsi generic sg3 type 0
kernel: sd 11:0:0:1: [sdd] 209715200 512-byte logical blocks: (107 GB/100 GiB)
kernel: sd 11:0:0:1: [sdd] Write Protect is off
kernel: sd 11:0:0:1: [sdd] Mode Sense: 97 00 10 08
kernel: sd 11:0:0:1: [sdd] Write cache: disabled, read cache: enabled, supports DPO and FUA
kernel:  sdd: sdd1

My only theory is that the timing of the process is a little off and Nova isn't seeing the volume available on the destination host and is aborting the migration. But there is no explicit error message.