Function

This API is used to reinstall an ECS OS. During the system disk reinstallation using the original image, the data disks of the ECS remain unchanged.

This API is an asynchronous API. After the OS reinstallation request is successfully delivered, a job ID is returned. This does not mean the reinstallation is complete. You need to call the API by referring to Querying Job Execution Status to query the job status. The SUCCESS status indicates that the reinstallation is successful.

After this API is called, the system uninstalls the system disk, uses the original image to create a system disk, and attaches it to the ECS. In this way, the OS is reinstalled.

Constraints

You can only use an image with Cloud-Init or Cloudbase-Init installed.
You can reinstall OS only on an ECS that is stopped or for which OS reinstallation has failed.
You are not allowed to reinstall the OS of an ECS that does not have the system disk.
You are not allowed to perform other operations when reinstalling the OS. Otherwise, reinstalling the OS will fail.

URI

POST /v2/{project_id}/cloudservers/{server_id}/reinstallos

Table 1 describes the parameters in the URI.

**Table 1** Parameter description
Parameter	Mandatory	Description
project_id	Yes	Specifies the project ID.
server_id	Yes	Specifies the ECS ID.

Request

Table 2 describes the request parameters.

**Table 2** Request parameters
Parameter	Mandatory	Type	Description
os-reinstall	Yes	Object	Definition Re-installs an ECS OS. For details, see Table 3. Constraints N/A Range N/A Default Value N/A

**Table 3** **os-reinstall** field description
Parameter	Mandatory	Type	Description
keyname	Yes	String	Definition Specifies the key name. Constraints N/A Range N/A Default Value N/A
userid	Yes	String	Definition Specifies the user ID. Constraints This parameter is mandatory when keyname is used. Range N/A Default Value N/A
metadata	No	Object	Definition Specifies metadata of the reinstalled ECS. For more information, see Table 4. Constraints N/A Range N/A Default Value N/A

**Table 4** **metadata** field description
Parameter	Mandatory	Type	Description
BYOL	No	String	Definition Specifies whether a user has the license of an image. Constraints N/A Range If this parameter is set to true, the license file delivered with the image is used, indicating that BYOL is used. If this parameter is set to a value other than true, BYOL is not used, and the license file provided by the cloud platform must be used. Default Value The default value is not true, indicating that BYOL is not used.
user_data	No	String	Definition Specifies the user data to be injected to the ECS during the creation. Text and text files can be injected. Examples Before base64 encoding: Linux #!/bin/bash echo user_test > /home/user.txt Windows rem cmd echo 111 > c:\aaa.txt After base64 encoding: Linux IyEvYmluL2Jhc2gKZWNobyB1c2VyX3Rlc3QgPiAvaG9tZS91c2VyLnR4dA== Windows cmVtIGNtZAplY2hvIDExMSA+IGM6XGFhYS50eHQ= For more details, see "Injecting User Data into ECSs" in the Elastic Cloud Server User Guide. Constraints The content of user_data must be encoded with base64. The maximum size of the content to be injected (before encoding) is 32 KB. Range N/A Default Value N/A
__system__encrypted	No	String	Definition Specifies the encryption field in metadata. Constraints N/A Range 0: indicates a non-encrypted disk. 1: indicates an encrypted disk. Default Value If this parameter does not exist, the system disk will not be encrypted by default.
__system__cmkid	No	String	Definition Specifies the CMK ID, which indicates encryption in metadata. Constraints This parameter must be used with __system__encrypted. NOTE: For details about how to obtain the CMK ID through HTTPS requests, see "Querying the Key List" in Key Management Service API Reference. Range N/A Default Value N/A

Response parameters

Table 5 describes the response parameters.

**Table 5** Response parameters
Parameter	Type	Description
job_id	String	Definition Specifies the job ID returned after a job is delivered. The job ID can be used to query the job execution progress. For details about how to query the job execution status based on job_id, see Job Status Management. Range N/A

For details about abnormal responses, see Responses (Jobs).

Example Request

After the ECS OS is reinstalled, use the password for login authentication. For security purposes, store the password in ciphertext in configuration files or environment variables.

POST https://{endpoint}/v2/{project_id}/cloudservers/{server_id}/reinstallos

{
    "os-reinstall": {
        "userid": "7e25b1da389f4697a79df3a0e5bd494e",
        "mode": "withStopServer"
    }
}

Reinstall an OS and use the key pair for login authentication after the reinstallation.

POST https://{endpoint}/v2/{project_id}/cloudservers/{server_id}/reinstallos

{
    "os-reinstall": {
        "keyname": "KeyPair-350b", 
        "userid": "7e25b1da389f4697a79df3a0e5bd494e"
    }
}

If the ECS OS is reinstalled using encrypted full-ECS images of the system disk, use the password for login authentication. For security purposes, store the password in ciphertext in configuration files or environment variables.

POST https://{endpoint}/v2/{project_id}/cloudservers/{server_id}/reinstallos

{
    "os-reinstall": { 
        "userid": "7e25b1da389f4697a79df3a0e5bd494e",
        "metadata": {
              "__system__encrypted": "1",
              "__system__cmkid": "83cdb52d-9ebf-4469-9cfa-e7b5b80da846"
        }
    }
}

Example Response

See Responses (Jobs).

{      
    "job_id": "ff80808288d41e1b018990260955686a" 
}

Returned Values

See Returned Values for General Requests.

Error Codes

See Error Codes.

Reinstalling an ECS OS (Using an Image with Cloud-Init Installed)