Data Transfers · Speed and advanced options
What is a dry run and how do I read its results?
Short answer: A dry run goes through the transfer without copying, replacing or deleting anything. Turn on Dry run (preview only) in New Transfer, start it, then read the Log card to see what would happen.
A dry run goes through the whole transfer without changing anything — no file is copied, replaced or deleted. It's the safe way to check a new Sync or Move before trusting it.
Turn on Dry run (preview only) at the bottom of New Transfer and click Start Transfer. When it finishes, select it in Data Transfers and read the Log card, which lists what would have been transferred and what would have been removed.
If it looks right, create the same transfer again with Dry run off.
Related: Does Sync (one-way) delete files? · Where is the transfer log?