Many thanks to Tony Mucci for this simple solution for Drupal8 Passwd resets:
From: https://medium.com/code-kings/drupal-8-how-to-manually-reset-an-admin-p…

The Raspberry Pi 3 Model B is the third generation Raspberry Pi with a 64-bit 1.2GHz quad-core processor, 1GB of RAM, WiFi (b/g/n), and Bluetooth 4.1!

The latest Raspberry Pi retains the same overall form factor as previous models ensuring compatibility with existing add-on boards (HATs) however some minor changes to the layout and more powerful processor mean we've redesigned our Pibow case.

root@pve:/var/lib/vz/dump# pct restore -storage local-lvm --rootfs 4 300 vzdump-lxc-200-2016_11_19-12_23_24.tar.gz
  Logical volume "vm-300-disk-1" created.
mke2fs 1.42.12 (29-Aug-2014)
Discarding device blocks: done                            
Creating filesystem with 1048576 4k blocks and 262144 inodes
Filesystem UUID: 602ba375-c829-40d2-a1bb-8275d5ce9407
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done                            
Writing inode tables: done                            

This was very useful for a corrupted song db in itunes:

You can use a playlist to collect dead tracks.
Create new regular playlist – Playlist1
Select whole library and drag to Playlist1
Create new Smart Playlist with the rule: Playlist is not Playlist1
Live updating checked – after you run it, uncheck live updating or you may not be able to delete tracks.
This playlist should contain all the dead tracks
Use shift-del to remove from library

This is a bit exciting for me - less so for anyone else I guess :(
But it has taken me a while to get to this point.

Took a snapshot backup from the office proxmox V3.x server, and brought it home t o convert to LXC (Linux Container) format on a proxmox 4.2 server (apparently LXC is the go nowadays - who knew?)

Here's the magic bit:

I have been grappling with this for a while - turns out it was something very simple:

grub-mkdevicemap -n
update-grub

root@pve:~# grub-mkdevicemap -n
root@pve:~# update-grub
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-2.6.32-39-pve
Found initrd image: /boot/initrd.img-2.6.32-39-pve
Found memtest86+ image: /boot/memtest86+.bin
Found memtest86+ multiboot image: /boot/memtest86+_multiboot.bin
done

Some other useful links for Proxmox setup:
https://pve.proxmox.com/wiki/Package_repositories

I have always found the boot area a difficult one to understand.
Take this link as an example:
http://paste.ubuntu.com/11527748/

And AFTER the repair:
http://paste.ubuntu.com/11527984/ <-- This one Failed...

Another try - it inlcuded a re-install of Grub
Please write on a paper the following URL:
http://paste.ubuntu.com/11529742/

That's the out put from my laptop after I munged the disk arrangement adding a larger drive.

install Boot-Repair in Ubuntu

drush upwd admin --password=mynewpassword

Could not login with user ID #0. This is typically caused by importing a MySQL database dump from a faulty tool [error] which re-numbered the anonymous user ID in the users table.