Why each next rsync is faster?

Node Operators FAQ
1

Hello,

There is a guide how to migrate a node: https://documentation.storj.io/resources/faq/migrate-my-node

Step 5. suggest running rsync several times until execution time decrease.

Could somebody explain, why running rsync command several times decrease it execution time? What is going on in the background when you run rsync first, second, third, etc. time?

Thank you.

2

rsync only copies the files that are missing or got changed --> execution time decreases each time as less and less files are different (only the ingress and deleted files changed)