Apr 26 - addendum

The last step, almost, in checking that a major upgrade has gone well is to double check the weekly backup.  Each week both the Linux environment, sans personal files on Public, such as photos & music, and not including the actual W10 VM, is backed up.  Separately, I backup the W10.  For both of these, I use the Linux dump command.  I used to use tar but dump is more efficient - faster and a smaller dumpfile.  These are run as cron jobs and I use logrotate to cycle them. 

Checking both of these today, I saw that both dump files were smaller.  That was somewhat expected with the move to 18.04 but not expected with the resizing of the Windows VM.  Going from 64gb to 80gb should have made the file larger; should have taken longer.  So ... I checked the log and sure enough, I could see the sectors being dumped and the clean completion, along with the better-than-before compression ratio ... great !

One thing that I have to relearn each time is that it's almost impossible to get a clean bootloader setup without unplugging all the other internal drives and turning off all the external drives, save the one being setup.  I tried again and failed to correctly edit the very detailed grub.cfg (which has an embedded comment to not edit) so I had to do the dirty job of opening the box and unplugging drives.  Then, later on, I ran into trouble when the system froze ... what is this ?  Windows ?  no ... after much googling wondering about corruption and trying to fix the mucked up screen resolution, I realized that what had happened - and why it couldn't properly detect my monitor - was that the monitor cable was loose after the aforementioned mucking about.  Right.

This time I created a USB drive boot for 18.04 and reinstalled grub (acronym Grand Unified Boot Loader) when booting from he usb.  Other times I have either done that online or with a cd.  Later, when I was trying to setup a usb windows boot, trying to fix that dang partition sizing issue, I ran into problems first with one sdhc drive and then another, gave up and created a boot dvd which worked but I ended up doing that restore / re-partition exercise.  

One other thing that I did was move that new 80gb file to a different drive before the restore.  That stopped the double hammering on the root drive.  I then copied it back. 

As usual, now that I've stumbled through this, I will be able to setup a second drive without quite as many stumbles.   Perhaps a couple of years from now, I'll remember ?  Nooooo