# Managing Lustre versions
FSx for Lustre currently supports multiple long-lerm support (LTS) Lustre versions released by the Lustre community. Newer LTS versions provide benefits such as performance enhancements, new features, and support for the latest Linux kernel versions for your client instances. You can upgrade your file systems to newer Lustre versions within minutes using the AWS Management Console, AWS CLI, or AWS SDKs.
FSx for Lustre currently supports Lustre LTS versions 2.10, 2.12, and 2.15. You can determine the LTS version of your FSx for Lustre file systems using the AWS Management Console or by using the [describe-file-systems](https://docs.aws.amazon.com/cli/latest/reference/fsx/describe-file-systems.html) AWS CLI command.
Before you perform a Lustre version upgrade, we recommend that you follow the steps described in [Best practices for Lustre version upgrades](#version-upgrade-best-practices).
**Topics**
+ [Best practices for Lustre version upgrades](#version-upgrade-best-practices)
+ [Performing the upgrade](#perform-upgrade)
## Best practices for Lustre version upgrades
We recommend following these best practices before upgrading the Lustre version of your FSx for Lustre file system:
+ **Test in a non-production environment:** Test a Lustre version upgrade on a duplicate of your production file system before upgrading your production file system. This ensures a smooth upgrade process for your production workload.
+ **Ensure client compatibility:** Verify that the Linux kernel versions running on your client instances are compatible with the Lustre version you plan to upgrade to. See [Lustre file system and client kernel compatibility](lustre-client-matrix.md) for details.
+ **Back up your data:**
+ For file systems not linked to S3: We recommend that you create an FSx backup before upgrading the Lustre version so that you have a known restore point for your file system. If automatic daily backups are enabled on your file system, Amazon FSx will automatically create a backup of your file system before upgrading.
+ For file systems linked to S3 We recommend ensuring that all changes have been exported to S3 before upgrading. If you have enabled automatic export, check that the [`AgeOfOldestQueuedMessage`](fs-metrics.md#auto-import-export-metrics) AutoExport metric is zero to confirm that all changes have been successfully exported to S3. If you have not enabled automatic export, you can run a manual data repository task (DRT) export to synchronize your file system with the S3 bucket before upgrading.
## Performing the upgrade
To upgrade your FSx for Lustre file system to a newer version, follow the listed steps:
1. **Unmount all clients:** Before initiating the upgrade, you must unmount the file system from all client instances accessing your file system. You can verify that all clients are successfully unmounted by using the `ClientConnections` metric on Amazon CloudWatch - this metric should display zero connections. The upgrade process will not proceed if any clients remain connected to the file system.
You can view the list of client network identifiers (NIDs) connected to the file system in the `.fsx/clientConnections` file stored at the root of your file system. This file is updated every 5 minutes. You can use the `cat` command to display the contents of the file, as in this example:
```
cat /test/.fsx/clientConnections
```
1. **Upgrade the Lustre version:** You can upgrade the Lustre version of your FSx for Lustre file system using the Amazon FSx console, the AWS CLI, or the Amazon FSx API. We recommend upgrading your file systems to the latest Lustre version supported by FSx for Lustre.
**To update the Lustre version of a file system (console)**
1. Open the Amazon FSx console at [https://console.aws.amazon.com/fsx/](https://console.aws.amazon.com/fsx/).
1. In the left navigation pane, choose **File systems**. In the **File systems** list, choose the FSx for Lustre file system that you want to update the Lustre version for.
1. For **Actions**, choose **Update file system Lustre version**. Or, in the **Summary** panel, choose **Update** next to the file system's **Lustre version** field. The **Update file system Lustre version** dialog box appears. The **Update file system Lustre version** dialog box appears.
1. For the **Select a new Lustre version** field, choose a Lustre version. The value you choose must be newer than the current Lustre version.
1. Choose **Update**.
**To update the Lustre version of a file system (CLI)**
To update the Lustre version of an FSx for Lustre file system, use the AWS CLI command [update-file-system](https://docs.aws.amazon.com/cli/latest/reference/fsx/update-file-system.html). (The equivalent API action is [UpdateFileSystem](https://docs.aws.amazon.com/fsx/latest/APIReference/API_UpdateFileSystem.html).) Set the following parameters:
+ Set `--file-system-id` to the ID of the file system that you are updating.
+ Set `--file-system-type-version` to a newer Lustre version for the file system that you are updating.
The following example updates the file system's Lustre version from 2.12 to 2.15:
```
aws fsx update-file-system \
--file-system-id fs-0123456789abcdef0 \
--file-system-type-version "2.15"
```
1. **Mount all clients:** You can monitor the progress of Lustre version updates by using the **Updates** tab in the Amazon FSx console or `describe-file-systems` in the AWS CLI. Once the Lustre version upgrade status shows as `Completed`, you can safely remount the file system on your client instances and resume your workload.