How to back up a Linux server with rsync

Quick answer: rsync copies directories over SSH and, after the first run, transfers only what changed. A single command like rsync -avz /var/www/ user@storage:/srv/backups/www/ is already a working backup; add --delete, excludes and a dated snapshot layout as you grow.

Overview

rsync is the workhorse of Linux backups: preinstalled almost everywhere, bandwidth-efficient and scriptable. This guide covers the flags that matter, what to include and exclude, and the hard-link trick that turns a plain mirror into space-efficient point-in-time snapshots.

Before you start

• SSH access to a backup target, ideally a Storage VPS with key authentication set up.
• A list of directories that actually hold state: typically /etc, /var/www, /home, database dumps.
• rsync on both sides: apt install rsync (Debian/Ubuntu) or dnf install rsync (AlmaLinux/Rocky).

Step-by-step guide

1. Start with a dry run to see what would be copied:

   rsync -avzn /var/www/ [email protected]:/srv/backups/www/

2. Run the real transfer (drop the n):

   rsync -avz /var/www/ [email protected]:/srv/backups/www/

   -a keeps permissions/owners/timestamps, -v shows progress, -z compresses in transit.
3. Exclude junk that wastes space:

   rsync -avz --exclude 'cache/' --exclude '*.tmp' /var/www/ [email protected]:/srv/backups/www/

4. Mirror deletions only when you also keep snapshots — --delete makes the copy exact but removes your safety net on its own.
5. Snapshots with hard links — unchanged files cost no extra space:

   TODAY=$(date +%F)
   rsync -avz --delete --link-dest=/srv/backups/www-latest \
     /var/www/ [email protected]:/srv/backups/www-$TODAY/
   ssh [email protected] "ln -sfn /srv/backups/www-$TODAY /srv/backups/www-latest"

Common issues

• Trailing slash confusion: /var/www/ copies the contents, /var/www copies the directory itself into the target — pick one convention and stick to it.
• Databases copied live: dump them first with mysqldump/pg_dump; raw datadir copies are corrupt more often than not.
• Root-owned files skipped: run the job as a user that can read everything you back up, or use sudo carefully.

When to contact support

rsync itself is standard Linux tooling; if transfers to your Cloud2Y Storage VPS stall or the network drops mid-sync repeatedly, open a ticket with timestamps and both server IPs.

Frequently asked questions

What do the rsync -avz flags actually do?

The -a flag preserves permissions, owners and timestamps while recursing; -v prints what is transferred; -z compresses data in transit, which speeds up transfers over the internet.

Should I use the --delete option with rsync?

Only when you also keep dated snapshots. With --delete the target mirrors every deletion, so on its own it happily propagates yesterday's mistake to your only backup copy.

How do rsync hard-link snapshots save space?

With --link-dest, unchanged files in a new dated directory are hard links to the previous snapshot, so each night costs only the size of changed files while looking like a full copy.

Related articles

• How to configure backups to a Storage VPS
• How to automate backups with cron
• Backup retention policy explained
• How to encrypt backups

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