# Manually installing SSM Agent on Amazon Linux 2 and Amazon Linux 2023 instances
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In most cases, the Amazon Machine Images (AMIs) for Amazon Linux 2 and Amazon Linux 2023 that are provided by Amazon come with Amazon Systems Manager Agent (SSM Agent) preinstalled by default. For more information, see [Find AMIs with the SSM Agent preinstalled](ami-preinstalled-agent.md).

In the event that SSM Agent isn’t preinstalled on a new Amazon Linux 2 or Amazon Linux 2023 instance, or if you need to manually reinstall the agent, use the information on this page to help you.

**Before you begin**  
Before you install SSM Agent on an Amazon Linux 2 or Amazon Linux 2023 instance, note the following:
+ For important information that applies to installation of SSM Agent on all Linux-based operating systems, see [Manually installing and uninstalling SSM Agent on EC2 instances for Linux](manually-install-ssm-agent-linux.md).
+ If you use a `yum` command to update SSM Agent on a managed node after the agent has been installed or updated using the SSM document `AWS-UpdateSSMAgent`, you might see the following message: `"Warning: RPMDB altered outside of yum."` This message is expected and can be safely ignored.

**Topics**
+ [Quick installation commands for SSM Agent on Amazon Linux 2 or Amazon Linux 2023](#quick-install-al2)
+ [Create custom agent installation commands for Amazon Linux 2 or Amazon Linux 2023 in your Region](#custom-url-al2)

## Quick installation commands for SSM Agent on Amazon Linux 2 or Amazon Linux 2023
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Use the following steps to manually install SSM Agent on a single instance. This procedure uses globally available installation files. 

**To install SSM Agent on Amazon Linux 2 or Amazon Linux 2023 using quick copy and paste commands**

1. Connect to your Amazon Linux 2 or Amazon Linux 2023 instance using your preferred method, such as SSH.

1. Copy the command for your instance’s architecture and run it on the instance.
**Note**  
Even though URLs in the following commands include an `ec2-downloads-windows` directory, these are the correct global installation files for Amazon Linux 2 and Amazon Linux 2023.   
 **x86\_64**   

   ```
   sudo yum install -y https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/linux_amd64/amazon-ssm-agent.rpm
   ```  
 **ARM64**   

   ```
   sudo yum install -y https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/linux_arm64/amazon-ssm-agent.rpm
   ```

1. (Recommended) Run the following command to verify that the agent is running.

   ```
   sudo systemctl status amazon-ssm-agent
   ```

   In most cases, the command reports that the agent is running, as shown in the following example.

   ```
   amazon-ssm-agent.service - amazon-ssm-agent
   Loaded: loaded (/usr/lib/systemd/system/amazon-ssm-agent.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2021-10-20 19:09:29 UTC; 4min 6s ago
               --truncated--
   ```

   In rare cases, the command reports that the agent is installed but not running, as shown in the following example.

   ```
   amazon-ssm-agent.service - amazon-ssm-agent
   Loaded: loaded (/usr/lib/systemd/system/amazon-ssm-agent.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Wed 2021-10-20 22:16:41 UTC; 18s ago
               --truncated--
   ```

   To activate the agent in these cases, run the following command.

   ```
   sudo systemctl start amazon-ssm-agent
   ```

## Create custom agent installation commands for Amazon Linux 2 or Amazon Linux 2023 in your Region
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When you install SSM Agent on multiple instances using a script or template, we recommend using installation files that are stored in the Amazon Web Services Region you're working in. 

For the following commands, we provide examples that use a publicly accessible S3 bucket in the US East (Ohio) Region (`us-east-2`). 

**Tip**  
You can also replace a global URL in the procedure [Quick installation commands for SSM Agent on Amazon Linux 2 or Amazon Linux 2023](#quick-install-al2) earlier in this topic with a custom Regional URL you construct.

In the following command, replace {{region}} with your own information. For a list of supported {{region}} values, see the **Region** column in [Systems Manager service endpoints](https://docs.amazonaws.cn/general/latest/gr/ssm.html#ssm_region) in the *Amazon Web Services General Reference*.

**x86\_64**  

```
sudo yum install -y https://s3.{{region}}.amazonaws.com/amazon-ssm-{{region}}/latest/linux_amd64/amazon-ssm-agent.rpm
```
See the following example.  

```
sudo yum install -y https://s3.us-east-2.amazonaws.com/amazon-ssm-us-east-2/latest/linux_amd64/amazon-ssm-agent.rpm
```

**ARM64**  

```
sudo yum install -y https://s3.{{region}}.amazonaws.com/amazon-ssm-{{region}}/latest/linux_arm64/amazon-ssm-agent.rpm
```
See the following example.  

```
sudo yum install -y https://s3.us-east-2.amazonaws.com/amazon-ssm-us-east-2/latest/linux_arm64/amazon-ssm-agent.rpm
```