rsync

Full-fidelity migration copy Preserve hardlinks, ACLs, xattrs, raw uid/gid for host migration; note: trailing slash matters rsync -aHAXv --numeric-ids /src/ user@<host>:/dst/ #rsync#network#security#troubleshooting Itemized dry-run diff Preview every change with itemize codes (>f, cd, *deleting) before touching files rsync -ai --dry-run --delete /src/ /dst/ #rsync#debug#troubleshooting Throttled transfer Cap bandwidth to 10 MB/s to avoid saturating the link; progress2 shows overall ETA rsync -a --bwlimit=10M --info=progress2 /src/ user@<host>:/dst/ #rsync#network#performance Hardlinked incremental snapshots Time-Machine-style backup: unchanged files hardlink to prev, only deltas use new space rsync -a --delete --link-dest=../prev /src/ ./$(date +%F)/ #rsync#disk#performance Resume large file transfer Resume interrupted big files and verify appended part by checksum; note: only safe if source unchanged rsync -a --partial --append-verify --info=progress2 big.img user@<host>:/dst/ #rsync#network#troubleshooting Non-standard SSH port + excludes Tunnel over custom SSH port and skip paths listed in excludes.txt (.git, node_modules, *.tmp) rsync -a -e "ssh -p 2222" --exclude-from=excludes.txt /src/ user@<host>:/dst/ #rsync#network#ci Checksum-based sync Compare by checksum not mtime+size; delete-after avoids removing files until transfer succeeds rsync -ac --delete-after /src/ /dst/ #rsync#troubleshooting#disk