Do NOT update working machines!!!

I used to work in an environment that required high reliability. Hot-swap spares were the norm and that includes software. If you were updating software, it was done on a second (or sometimes even third) device to ensure that you always had 1 working production device and often a working spare as well. This philosophy is required in some industries, but many have moved away from it due to the cost. For a long time, downtime was forbidden. Now consultants or MBAs model the cost of downtime and can often justify it as critical savings in the short term. My local hospital recently rolled out a software update that brought down all their OR suites for over a week due to a driver issue.

I've been using Debian (and offshoots) for over 20 years and *nix before that. Original sysadmins were taught the importance of backups before updates as the OS itself doesn't provide a mechanism to roll back. There is an opportunity to provide better instructions to users on how to migrate a system safely, but it is a lot of work and there is always some risk.

I have linuxcnc running in a NixOS VM for simulations and might move my main controller to this one day.

I agree there is potentialy risk in upgrade an working machine.
I like have newest system with newest abilities, so I upgrade/install system very often.
Sometimes there is no problems, sometimes system or Linuxcnc became useless...
My last bad experience is MESA "error finishing read" error after upgrade kernel (some versions of 6.12 kernel works well, some not).
The best solution is full backup and two or few disks with many partitions.
The Debian 13 with LinuxCNC installed only for control the machine (xfce4, no CAD/CAM etc.) fits in 8 GB disk space.
It is only a few minutes for copy whole of that partition with dd...

In other side, I know the man who has above twenty (!!!) commercial (!!!) installations of Wheezy on very old commputers with LPT ports.
If you don't know what it means, I explain : 32bit systems with RTAI kernel (no realtime ethernet) with hardware in end of their life...
Any updates of this museum are imposible, and any old configs will not work with modern LinuxCNC... 

tommylight wrote:

I would really appreciate if someone else would write something about this, and i will gladly delete this.

Anyone?

For me it really simple. I rely on my machines for my livelihood. Once I had it working satisfactorily, there was no need for any updates. These controls function exactly the same as the original controls, an update isn't going to change that.