Reboot twice per upgrade

Hi Guys,
I have several Mender clients that are running Ubuntu 18.
I want to upgrade them all to Ubuntu 22 but cannot use the OS upgrade.
I want to upgrade it per Ubuntu’s Instructions, by calling apt and similar commands to pull the official Ubuntu 20, and later ubuntu 22.

I want to use the mender client single-file or (some similar custom update module), however, the OS upgrade process requires 2 reboots - one after getting to Ubuntu 20, and another after 22.

Is doing more than a single reboot supported?
Or must I use 2 artifacts one for each OS upgrade process?
Do you have any idea how to use mender for that?


Hi @zivkapl,

My gut feeling is that a custom Update Module is the way to go, basically a hybrid of the single-file and script one, but offloading the actual process until after the file has actually be deployed, then hooking into OS mechanisms for triggering the upgrade process. It pretty sure can be done, but will require very careful crafting of the mechanism, and a lot of testing and safeguarding as such a script that does not use the A/B mechanism has no rollback and therefore introduces a lot of breaking points.

Some material for thought:

  • making sure the mender-connect service stays alive so you can at least interactively try to fix things
  • or repartition and introduce the A/B setup


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