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9 - Directory Transfer with Rsync ​

Note: Just a command-line exercise. No terraform needed.

The Problem: scp copies blindly. If a transfer fails halfway, or you just changed one file in a specific directory, scp copies everything again. Slow and wasteful.

The Solution: rsync only copies the differences (deltas). It's faster, supports resuming, and preserves permissions/timestamps.

Prerequisites ​

  • rsync installed on both local and remote machines (sudo apt install rsync)

Objective ​

Use rsync to efficiently sync directories over SSH.

How-to ​

1. Basic Sync ​

Copy local directory to remote:

bash
rsync -avz -e ssh ./local_dir/ user@remote:~/backup/

The Flags:

  • -a: Archive mode (preserves permissions, times, owners - indispensable)
  • -v: Verbose (tell me what you're doing)
  • -z: Compress (save bandwidth)
  • -e ssh: Use SSH as the transport

2. Sync Back (Restore) ​

To pull files back (remote to local), just flip the arguments:

bash
rsync -avz -e ssh user@remote:~/backup/ ./local_restore/

Trailing Slashes Matter!

  • src/ (with slash) = copy the contents of src.
  • src (no slash) = copy the directory itself (creating dest/src).