# Change host specifications - ResizeUHostInstance

## Overview

Modify the resource configuration of the specified UHost instance, such as the number of CPU cores, memory capacity size, network enhancement, etc. Please refer to [UHost Model Description](api/uhost-api/uhost_type) for the optional configuration range.

 > 💡 If you need to adjust the disk size, please call ResizeAttachedDisk.

 > ℹ️ 1. Before modifying the configuration, please make sure that the instance has been shut down.<br />2. After changing the disk space size, please follow the instructions to operate in the operating system after startup.


## Definition

### Public Parameters

| Parameter Name | Type | Description Information | Required |
|:---|:---|:---|:---|
| **Action**     | string  | Corresponding API command name, the current API is `ResizeUHostInstance`.                      | **Yes** |
| **PublicKey**  | string  | The user's public key can be obtained from [Console](https://console.scloudsg.com/uaccount/api_manage)                                             | **Yes** |
| **Signature**  | string  | User signature generated based on public key and API command, see [Signature Algorithm](/docs/api/summary/signature.md)  | **Yes** |

### Request Parameters

| Parameter Name | Type | Description Information | Required |
|:---|:---|:---|:---|
| **Region** | string | Region. See [List of Regions and Availability Zones](/docs/api/summary/regionlist) |**Yes**|
| **Zone** | string | Availability Zone. See [Availability Zone List](/docs/api/summary/regionlist) |No|
| **ProjectId** | string | Project ID. If not filled in, the default project is used, sub-accounts must be filled in. Please refer to the [GetProjectList interface](/docs/api/summary/get_project_list). |No|
| **UHostId** | string | UHost Instance ID See [DescribeUHostInstance](api/uhost-api/describe_uhost_instance) |**Yes**|
| **CPU** | int | Number of virtual CPU cores. Optional parameters: 1-240 (optional range related to UHostType). The default value is the current instance's CPU core number. |No|
| **Memory** | int | Memory size. Unit: MB. Range: [1024, 1966080], must be a multiple of 1024 (optional range is related to UHostType). The default value is the current instance's memory size. |No|
| **GPU** | int | Number of GPU card cores. Only GPU models support this field (optional range related to MachineType+GpuType). |No|
| **NetCapValue** | int | Network card upgrade or downgrade (1 indicates upgrade, 2 indicates downgrade, 0 indicates no change) |No|
| **AutoStart** | boolean | Whether to immediately power on after the expansion is completed, default is false,<br />If set to true, power on immediately after successful expansion;<br />Spot and Postpaid chargeType  uhost do not support the current feature; |No|

### Response Field

| Field Name | Type | Description Information | Required |
|:---|:---|:---|:---|
| **RetCode** | int | Return status code. If it is 0, it means successful return. If it is not 0, it means failure. |**Yes**|
| **Action** | string | Operation command name. |**Yes**|
| **Message** | string | Returns an error message, providing detailed description when `RetCode` is non-zero. |No|
| **UHostId** | string | UHost Instance ID |No|




## Example

### Request Example
    
```
https://api.scloudsg.com/?Action=ResizeUHostInstance
&Region=cn-bj2
&Zone=cn-bj2-04
&ProjectId=org-xxx
&UHostId=uhost-xxx
&CPU=4
&Memory=2048
&GPU=5
&GPU=6
&AutoStart=false
&AutoStart=false
&AutoStart=true
&AutoStart=true
```

### Response Example
    
```json
{
  "Action": "ResizeUHostInstanceResponse",
  "RetCode": 0,
  "UHostId": "uhost-xxx"
}
```