Update IoT Edge for Linux on Windows

Article
03/27/2024

Applies to: IoT Edge 1.4

Important

IoT Edge 1.4 is the supported release. If you are on an earlier release, see Update IoT Edge.

As the IoT Edge for Linux on Windows (EFLOW) application releases new versions, you'll want to update your IoT Edge devices for the latest features and security improvements. This article provides information about how to update your IoT Edge for Linux on Windows devices when a new version is available.

With IoT Edge for Linux on Windows, IoT Edge runs in a Linux virtual machine hosted on a Windows device. This virtual machine is pre-installed with IoT Edge, and has no package manager, so you can't manually update or change any of the VM components. Instead, the virtual machine is managed with Microsoft Update to keep the components up to date automatically.

The EFLOW virtual machine is designed to be reliably updated via Microsoft Update. The virtual machine operating system has an A/B update partition scheme to utilize a subset of those to make each update safe and enable a roll-back to a previous version if anything goes wrong during the update process.

Each update consists of two main components that may get updated to latest versions. The first one is the EFLOW virtual machine and the internal components. For more information about EFLOW, see Azure IoT Edge for Linux on Windows composition. This also includes the virtual machine base operating system. The EFLOW virtual machine is based on Microsoft CBL-Mariner and each update provides performance and security fixes to keep the OS with the latest CVE patches. As part of the EFLOW Release notes, the version indicates the CBL-Mariner version used, and users can check the CBL-Mariner Releases to get the list of CVEs fixed for each version.

The second component is the group of Windows runtime components needed to run and interop with the EFLOW virtual machine. The virtual machine lifecycle and interop is managed through different components: WSSDAgent, EFLOWProxy service and the PowerShell module.

EFLOW updates are sequential and you'll require to update to every version in order, which means that in order to get to the latest version, you'll have to either do a fresh installation using the latest available version, or apply all the previous servicing updates up to the desired version.

To find the latest version of Azure IoT Edge for Linux on Windows, see EFLOW releases.

Update using Microsoft Update

To receive IoT Edge for Linux on Windows updates, the Windows host should be configured to receive updates for other Microsoft products. By default, Microsoft Updates will be turned on during EFLOW installation. If custom configuration is needed after EFLOW installation, you can turn this option On/Off with the following steps:

Open Settings on the Windows host.
Select Updates & Security.
Select Advanced options.
Toggle the Receive updates for other Microsoft products when you update Windows button to On.

Update using Windows Server Update Services (WSUS)

On premises updates using WSUS is supported for IoT Edge for Linux on Windows updates. For more information about WSUS, see Device Management Overview - WSUS.

Offline manual update

In some scenarios with restricted or limited internet connectivity, you may want to manually apply EFLOW updates offline. This is possible using Microsoft Update offline mechanisms. You can manually download and install an IoT Edge for Linux on Windows updates with the following steps:

Check the current EFLOW installed version. Open Settings, select Apps -> Apps & features search for Azure IoT Edge.
Search and download the required update from EFLOW - Microsoft Update catalog.
Extract AzureIoTEdge.msi from the downloaded .cab file.
Install the extracted AzureIoTEdge.msi.

Managing Microsoft Updates

As explained before, IoT Edges for Linux on Windows updates are serviced using Microsoft Update channel, so turn on/off EFLOW updates, you'll have to manage Microsoft Updates. Listed below are some of the ways to automate turning on/off Microsoft updates. For more information about managing OS updates, see OS Updates.

CSP Policies - By using the Update/AllowMUUpdateService CSP Policy - For more information about Microsoft Updates CSP policy, see Policy CSP - MU Update.
Manually manage Microsoft Updates - For more information about how to Opt-In to Microsoft Updates, see Opt-In to Microsoft Update.

Migration between EFLOW 1.1LTS and EFLOW 1.4LTS

IoT Edge for Linux on Windows doesn't support migrations between the different release trains. If you want to move from the 1.1LTS or 1.4LTS version to the Continuous Release (CR) version or viceversa, you'll have to uninstall the current version and install the new desired version.

Migration between EFLOW 1.1LTS to EFLOW 1.4LTS was introduced as part of EFLOW 1.1LTS (1.1.2212.12122) update. This migration will handle the EFLOW VM migration from 1.1LTS version to 1.4LTS version, including the following:

IoT Edge runtime
IoT Edge configurations
Containers
Networking and VM configuration
Stored files

To migrate between EFLOW 1.1LTS to EFLOW 1.4LTS, use the following steps.

Get the latest Azure EFLOW 1.1LTS (1.1.2212.12122) update. If you're using Windows Update, Check Updates to get the latest EFLOW update.
For auto-download migration (needs Internet connection), skip this step. If the EFLOW VM has limited/no internet access, download the necessary files before starting the migration.
- 1.4.2.12122 Standalone MSI
- 1.4.2.12122 Update MSI
Open an elevated PowerShell session
Start the EFLOW migration

Note

You can migrate with one single cmdlet by using the -autoConfirm flag with the Start-EflowMigration cmdlet. If specified Confirm-EflowMigration doesnt needs to be called to proceed with 1.4 migration.
1. If you're using the auto-download migration option run the following cmdlet
```
Start-EflowMigration
```
2. If you download the MSI on Step 2, use the downloaded files to apply the migration
```
Start-EflowMigration -standaloneMsiPath "<path-to-folder>\AzureIoTEdge_LTS_1.4.2.12122_X64.msi" 
```
Confirm the EFLOW migration
1. If you're using the auto-download migration option run the following cmdlet
```
Confirm-EflowMigration
```
2. If you download the MSI on Step 2, use the downloaded files to apply the migration
```
Confirm-EflowMigration -updateMsiPath "<path-to-folder>\AzureIoTEdge_LTS_Update_1.4.2.12122_X64.msi" 
```

Warning

If for any reason the migration fails, the EFLOW VM will be restored to its original 1.1LTS version. If you want to cancel the migration or manually restore the EFLOW VM to prior state, you can use the following cmdlets Start-EflowMigration and then Restore-EflowPriorToMigration.

For more information, check Start-EflowMigration, Confirm-EflowMigration and Restore-EflowPriorToMigration cmdlet documentation by using the Get-Help <cmdlet> -full command.

Next steps

View the latest IoT Edge for Linux on Windows releases.