# Detaching an EVS Disk from a BMS (Native OpenStack API)

#### Function

This API is used to detach an EVS disk from a BMS.

#### Constraints

If a BMS is stopped, disks can be detached from it without any limitation on the OS. If a BMS is in running state, the constraints are as follows:

- Before detaching an EVS disk from a Linux BMS, log in to the BMS, run the unmount command to disassociate the disk to be detached from the file system, and ensure that no program is reading data from or writing data to the disk. Otherwise, the disk will fail to be detached.
- Before detaching an EVS disk from a running Windows BMS, ensure that no program is reading data from or writing data to the disk. Otherwise, data will be lost.

#### URI

DELETE /v2.1/{project_id}/servers/{server_id}/os-volume_attachments/{volume_id}

Table 1 lists the parameters.

Table 1 Parameter description
Parameter | Mandatory | Description
--- | --- | ---
project_id | Yes | Specifies the project ID. For how to obtain the project ID, see Obtaining Required Information.
server_id | Yes | Specifies the BMS ID. You can obtain the BMS ID from the BMS console or using the Querying BMSs (Native OpenStack API) API.
volume_id | Yes | Specifies the EVS disk ID. You can query attached EVS disks attached to a BMS using the Querying Information About the Disks Attached to a BMS (Native OpenStack API) API.

#### Request

- Request parameters

  None

- Example request

      1

      DELETE https://{ECS Endpoint}/v2.1/c685484a8cc2416b97260938705deb65/servers/95bf2490-5428-432c-ad9b-5e3406f869dd/os-volume_attachments/b53f23bd-ee8f-49ec-9420-d1acfeaf91d6

#### Response

N/A

#### Returned Values

Normal values

Returned Values | Description
--- | ---
200 | The request has been successfully processed.

For details about other returned values, see Status Codes.

#### Error Codes

See Error Codes.

Parent topic: BMS Disk Management