How to kick off the whole process:

sudo mkdir -p /mnt/tmpfs
sudo mount -o size=2G -t tmpfs none /mnt/tmpfs
mkdir -p /mnt/tmpfs/migrate/pending/12345
cd /mnt/tmpfs/migrate/pending/12345
tar ztvf /srv/www/wordpress-default/public_html/content.tgz
cd /mnt/tmpfs/
dirsplit -m -e1 -s 5M migrate
ls /mnt/tmpfs/|parallel -j10 'wp bigmig -f /mnt/tmpfs/{}'

You can get a database export and a sample content export of 10,000 posts from:
https://github.com/ivankruchkoff/wp-bigmig/releases/download/v1.0.0/exports.tgz

Video Overview
https://www.youtube.com/watch?v=mvRGdL4yyLw

Larger datasets available
https://webhose.io/datasets

WordCamp Presentation Sldies
https://www.slideshare.net/IvanK12/wordcamp-ottawa-wp-big-mig