Saturday, September 07, 2019

Mickey Mouse Linux & UNIX




Here in England, Marcus and Agata have made quite some considerable investment in Raspberry Pi.   This computer, or more accurately, a lot of them are busy 24x7 in many aspects of our home automation.

Not only are they low power, but inexpensive, and extremely small and portable.   Useful, if you know, one may to leave the (BREXIT) country in a hurry.

Recently Marcus has of course been using and developing on the latest and greatest Raspberry Pi 4.   This is a considerable advance on the Raspberry 3B+ hardware and a good summary would be here


And now the Trauma Begins


(The glasses are out, it's getting serious now)


At a minimum all respectable Software (or Software and Hardware) vendors always provide

- A documented way to backup and restore your computer

I mean using a 'bare metal' technique.  I explicitly don't mean, re-install the Operating System,  re-install your applications, perform all the tailoring you made, restore your data

I mean you make a snapshot of your entire computer into usually a single file.   Then if total disaster strikes you can restore it back to the instant the full backup was made.  OS, applications, data, settings, the whole caboodle.


- A documented way to migrate from one level of the OS to the next whilst preserving any existing applications

- A documented way to move from one hardware platform to the next.

But Guess what ...

- The Raspberry Pi 3B+ runs a version of the Operating System called Stretch.   There is no guaranteed way to move from Stretch to the new level called Buster

- The Raspberry Pi 4B runs Buster only.  It cannot run Stretch

- Even if you could sneakily upgrade your existing 3B+ to run the Buster level,  then if you backup your microSD card or exactly duplicate it and take it to a Raspberry Pi 4B

It does not boot

Yes, the recommendation is, the official solution is

01 Download the Buster software
02 On the Pi 4B perform a clean install
03 Install your applications afresh
04 Make all the tailoring afresh

What kind of Mickey Mouse Linux and Hardware am I dealing with here?

In all my years of working with proper UNIX  (AIX is my prime example) there was a single command that could produce a bootable backup tape or image.



Why This Never Works

A non trivial computer system does not log every change to every install or modification of your system.  It could in theory be done, but it never is.  Just think about your own computer system.  Do you maintain such a log?  Of every configuration change you made, say to your multiply year old system?  Do you even remember the sequence in which your changes were made (because that is often relevant).

And so I was absolutely gobsmacked that this 01 - 04 idealist and unworkable solution is that which is recommended.

The Rebuttals Are

- This is a low cost computer with a free Operating System.  What do you expect?

- If you were professional you would have made the log that you suggest


More Late Nights

I'm still looking for a solution other than leaving our current Webservers (for example) on their 3B+ platforms.   When it comes it will be of course obvious and not so serious, and I'll say things like "of course I knew that was possible"






Not so Serious