Compress files with xz and upload archive to google cloud

xz_to_google_cloud.md

I always forget these steps and have to google for them, even though they're super simple

Prereq:

• pip install gsutil
• gsutil config, have your project id ready.

1. tar --create --verbose --xz --file images.tar.xz /directory/containing/images/*
2. gsutil cp images.tar.xz gs://<bucket name>

to extract: tar -xf file.tar.xz

xz is supposed to be the "best" general purpose compression algorithm in terms of compression ratio, but its also slow.