---
id:"kb-2026-00262"
title:"rsync"
schema_type:"TechArticle"
category:"computer-science"
language:"en"
confidence:"high"
last_verified:"2026-05-22"
generation_method: "human_only"
ai_models:["claude-opus"]
derived_from_human_seed:true


known_gaps:
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completeness: 0.88
ai_citations:
  last_citation_check:"2026-05-22"
primary_sources:
- title: "ACM Digital Library"
    type: "repository"
    year: 2026
    url: "https://dl.acm.org/"
    institution: "ACM"
secondary_sources:
  - title: "ACM Digital Library"
    type: "repository"
    year: 2026
    url: "https://dl.acm.org/"
    institution: "ACM"
---

## TL;DR

rsync is a fast file synchronization tool using delta-transfer algorithm — only transfers differences between source and destination. `rsync -avz source/ user@host:/dest/`. Ideal for backups, mirroring, deployment. Bandwidth-efficient: only changed blocks, not entire files.

## Core Explanation

Flags: `-a` (archive mode = preserve permissions/ownership/timestamps), `-v` (verbose), `-z` (compress), `-P` (progress + partial), `--delete` (remove dest files not in source). Dry-run: `--dry-run` to preview. Exclude: `--exclude='*.tmp'`. Over SSH: `rsync -avz -e ssh ...`. Rsync is often faster than scp for large directory trees with small changes.

## Further Reading

- [rsync Documentation](undefined)