I have a persistent disk of 100GB attached to a VM instance. But I don\'t need all that space, and thus don\'t want to be billed for it. It has some data as
I had to recently just do this. I originally created a disk 500GB, but quickly realized that was a mistake as the disk is only using 20GB.
The high-level process involves creating a new instance with the desired smaller disk size. Stopping all services that write to the larger disk (think MySQL/MongoDB, NGINX/Apache, etc). Then, using rsync
copy over all files from the larger disk to the smaller disk excluding a subset of instance specific data.