rsync

rsync -auhv --delete --force --size-only --progress -n {SRC} {DST}

• -a: Archive (same as -rlptgoD, no -A,-X,-U,-N,-H)
• -r: Recursive
• -l: Copy symlinks as symlinks
• -p: Preserve permissions
• -t: Preserve modification times
• -g: Preserve group
• -o: Preserve owner (super-user only)
• -D: Preserve device files (super-user only) and preserve special files
• -u: Skip files that are newer on the receiver
• -h: Output numbers in a human-readable format
• -v: Increase verbosity
• --delete: Delete extraneous files from dest dirs
• --force: Force deletion of dirs even if not empty
• --progress: Show progress during transfer
• -n: Dry-run (list only, nothing is changed)
• -e 'ssh -p 22': Use ssh on port 22
• --partial: Preserve partially uploaded files
• -P: Combines --partial and --progress
• --append: Continues partial uploaded files

Omit the -n dry-run flag if everything seem in order.

The source {SRC} and destination {DST}must end with a / if they are directories, otherwise the source folder is created within the target.

Sync via ssh

Make sure rsync is installed on both systems.

rsync -avP --append -e 'ssh -p 22' /src/ username@server:/dst