unity replication fails on UnityVSA

[Sam Wan]

When using UnityVSA for unity replication, it fails with below errors:
======
2020-05-26 02:13:04.893 7 ERROR cinder.scheduler.filter_scheduler [req-02f16b50-7dcd-4928-adaa-65ecfbc4742c 96b61db3ce86496795265858c5cf8a3c 9b627fbc434f40cdb5483322943cecde - default default] │
Error scheduling 1b08a2fe-901f-4c9e-ad63-8e8a2155766e from last vol-service: hostgroup@unity-primary#pool1 : ['Traceback (most recent call last): │
', ' File /usr/lib/python3.6/site-packages/taskflow/engines/action_engine/executor.py, line 53, in _execute_task │
    result = task.execute(**arguments) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1113, in execute │
    context, volume, **volume_spec) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1079, in _create_raw_volume │
    exception=ex) │
', ' File /usr/lib/python3.6/site-packages/oslo_utils/excutils.py, line 220, in __exit__ │
    self.force_reraise() │
', ' File /usr/lib/python3.6/site-packages/oslo_utils/excutils.py, line 196, in force_reraise │
    six.reraise(self.type_, self.value, self.tb) │
', ' File /usr/lib/python3.6/site-packages/six.py, line 693, in reraise │
    raise value │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1071, in _create_raw_volume │
    ret = self.driver.create_volume(volume) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/driver.py, line 122, in create_volume │
    return self.adapter.create_volume(volume) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/adapter.py, line 395, in create_volume │
    model_update = self.setup_replications(lun, model_update) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/adapter.py, line 346, in setup_replications │
    \'Cannot find it.\') % remote_serial_number) │
', 'cinder.exception.VolumeBackendAPIException: Bad or unexpected response from the storage volume backend API: Setup replication to remote system VIRT2021GWL84H failed.Cannot find it. │
']
...
2020-05-26 02:13:05.805 7 ERROR cinder.scheduler.filter_scheduler [req-02f16b50-7dcd-4928-adaa-65ecfbc4742c 96b61db3ce86496795265858c5cf8a3c 9b627fbc434f40cdb5483322943cecde - default default] │
Error scheduling 1b08a2fe-901f-4c9e-ad63-8e8a2155766e from last vol-service: hostgroup@unity-primary#pool1 : ['Traceback (most recent call last): │
', ' File /usr/lib/python3.6/site-packages/taskflow/engines/action_engine/executor.py, line 53, in _execute_task │
    result = task.execute(**arguments) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1113, in execute │
    context, volume, **volume_spec) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1079, in _create_raw_volume │
    exception=ex) │
', ' File /usr/lib/python3.6/site-packages/oslo_utils/excutils.py, line 220, in __exit__ │
    self.force_reraise() │
', ' File /usr/lib/python3.6/site-packages/oslo_utils/excutils.py, line 196, in force_reraise │
    six.reraise(self.type_, self.value, self.tb) │
', ' File /usr/lib/python3.6/site-packages/six.py, line 693, in reraise │
    raise value │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/flows/manager/create_volume.py, line 1071, in _create_raw_volume │
    ret = self.driver.create_volume(volume) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/driver.py, line 122, in create_volume │
    return self.adapter.create_volume(volume) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/adapter.py, line 385, in create_volume │
    is_compressed=params.is_compressed) │
', ' File /usr/lib/python3.6/site-packages/cinder/volume/drivers/dell_emc/unity/client.py, line 79, in create_lun │
    is_compression=is_compressed) │
', ' File /usr/local/lib/python3.6/site-packages/storops/unity/resource/pool.py, line 114, in create_lun │
    is_compression=is_compression) │
', ' File /usr/local/lib/python3.6/site-packages/storops/unity/resource/lun.py, line 132, in create │
    resp.raise_if_err() │
', ' File /usr/local/lib/python3.6/site-packages/storops/unity/resp.py, line 131, in raise_if_err │
    raise ex_clz(self.error) │
', 'storops.exception.UnityException: The specified LUN name has already been reserved or LUN with this name already exists. (Error Code:0x6700210) │
'] │

===

[Ryan Liang (ryan-liang)]

Unity driver uses secondary IP to get the remote serial number then uses this serial number to filter the remoteSystem on primary Unity.
The problem here is the name and serial number of UnityVSA are not the same while these two variables are the same on physical machines.