How to return to the previous installed Miris version ?

This article is dedicated to Miris station administrators who need to revert to an earlier Miris version.

Miris stations use an update system based on dedicated "A/B" slots for on-board systems.

This means that two versions are always available: the latest installed update and the previous version.

So, if the newly installed update is unstable or introduces a regression, it is possible to restart on the previously installed version.

First of all, check which was the penultimate update installed on the machine via your Miris Manager. This will tell you which version you are downgrading to.

To do this, from the remote control panel of a Miris station connected to your Miris Manager, click on the "Settings" button, then the link on the left entitled "Upgrades history".

You will get a version table such as the following:

In this example, the current version is 3.1.0 and the other deployed version is 3.0.2. We could therefore revert to version 3.0.2 if version 3.1.0 proves unstable.

You then have two ways of reverting to the previous version:

• remotely from the control panel of your Miris station, using the command line with the virtual terminal
• physically, using a USB keyboard and HDMI screen

You can use the station remote terminal to enter the following command:

rauc status mark-bad && /sbin/shutdown -r now

After executing the command, the station will restart on the previous version.

To help you, we recommend that you read the "Miris diagnostics" article, "Command line" chapter

If you are not comfortable using the command line, you can connect a USB keyboard and HDMI monitor to the station. Then, when you power the station on, you can choose from the start menu to boot into the previous version via the corresponding Slot A or Slot B input. In this case, Slot A will be version 3.0.2.

We hope you have found this article useful. Please feel free to consult the "Miris" documentation to learn more.