I request the bug reporter to close the bug as this bug is already fixed in latest(Rock). Here is my analysis. nova volume-attach d709f9d8-e9ea-4c07-a83c-350689d27919 54bc2524-a0c5-4908-9ea2-726708667702 +----------+--------------------------------------+ | Property | Value | +----------+--------------------------------------+ | device | /dev/vdb | | id | 54bc2524-a0c5-4908-9ea2-726708667702 | | serverId | d709f9d8-e9ea-4c07-a83c-350689d27919 | | volumeId | 54bc2524-a0c5-4908-9ea2-726708667702 | +----------+--------------------------------------+ select * from block_device_mapping where instance_uuid='d709f9d8-e9ea-4c07-a83c-350689d27919'; +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ | created_at | updated_at | deleted_at | id | device_name | delete_on_termination | snapshot_id | volume_id | volume_size | no_device | connection_info | instance_uuid | deleted | source_type | destination_type | guest_format | device_type | disk_bus | boot_index | image_id | tag | attachment_id | uuid | +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ | 2018-05-07 08:26:27 | 2018-05-07 08:26:35 | NULL | 7 | /dev/vdb | 0 | NULL | 54bc2524-a0c5-4908-9ea2-726708667702 | 4 | NULL | {"status": "reserved", "detached_at": "", "volume_id": "54bc2524-a0c5-4908-9ea2-726708667702", "attach_mode": null, "driver_volume_type": "iscsi", "instance": "d709f9d8-e9ea-4c07-a83c-350689d27919", "attached_at": "", "serial": "54bc2524-a0c5-4908-9ea2-726708667702", "data": {"access_mode": "rw", "target_discovered": false, "encrypted": false, "qos_specs": null, "target_iqn": "iqn.2010-10.org.openstack:volume-54bc2524-a0c5-4908-9ea2-726708667702", "target_portal": "127.0.0.1:3260", "volume_id": "54bc2524-a0c5-4908-9ea2-726708667702", "target_lun": 1, "device_path": "/dev/sdb", "auth_password": "sbU7oRZje9snVL9U", "auth_username": "tr5KqceTr7vAjiXQV22W", "auth_method": "CHAP"}} | d709f9d8-e9ea-4c07-a83c-350689d27919 | 0 | volume | volume | NULL | NULL | NULL | NULL | NULL | NULL | b2e440e2-690e-472c-9c77-5deadf723243 | 68d0593b-d4fa-47b9-9428-f57f8da1c5ee | +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ 1 row in set (0.00 sec) again attaching the instance with same volume ID nova volume-attach d709f9d8-e9ea-4c07-a83c-350689d27919 54bc2524-a0c5-4908-9ea2-726708667702 ERROR (BadRequest): Invalid volume: volume 54bc2524-a0c5-4908-9ea2-726708667702 already attached (HTTP 400) (Request-ID: req-6a3052b6-fa92-4542-b0bb-80195c567f42) select * from block_device_mapping where instance_uuid=e_uuid='d709f9d8-e9ea-4c07-a83c-350689d27919'; +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ | created_at | updated_at | deleted_at | id | device_name | delete_on_termination | snapshot_id | volume_id | volume_size | no_device | connection_info | instance_uuid | deleted | source_type | destination_type | guest_format | device_type | disk_bus | boot_index | image_id | tag | attachment_id | uuid | +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ | 2018-05-07 08:26:27 | 2018-05-07 08:26:35 | NULL | 7 | /dev/vdb | 0 | NULL | 54bc2524-a0c5-4908-9ea2-726708667702 | 4 | NULL | {"status": "reserved", "detached_at": "", "volume_id": "54bc2524-a0c5-4908-9ea2-726708667702", "attach_mode": null, "driver_volume_type": "iscsi", "instance": "d709f9d8-e9ea-4c07-a83c-350689d27919", "attached_at": "", "serial": "54bc2524-a0c5-4908-9ea2-726708667702", "data": {"access_mode": "rw", "target_discovered": false, "encrypted": false, "qos_specs": null, "target_iqn": "iqn.2010-10.org.openstack:volume-54bc2524-a0c5-4908-9ea2-726708667702", "target_portal": "127.0.0.1:3260", "volume_id": "54bc2524-a0c5-4908-9ea2-726708667702", "target_lun": 1, "device_path": "/dev/sdb", "auth_password": "sbU7oRZje9snVL9U", "auth_username": "tr5KqceTr7vAjiXQV22W", "auth_method": "CHAP"}} | d709f9d8-e9ea-4c07-a83c-350689d27919 | 0 | volume | volume | NULL | NULL | NULL | NULL | NULL | NULL | b2e440e2-690e-472c-9c77-5deadf723243 | 68d0593b-d4fa-47b9-9428-f57f8da1c5ee | +---------------------+---------------------+------------+----+-------------+-----------------------+-------------+--------------------------------------+-------------+-----------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------+---------+-------------+------------------+--------------+-------------+----------+------------+----------+------+--------------------------------------+--------------------------------------+ 1 row in set (0.00 sec) Working Fine. Thanks