Where rsync fits.

1. Understand the connection

rsync works with filesystems and rsync/remote-shell endpoints. It does not upload directly to S3. ArcaCipher has no announced SSH login or rsync daemon, so do not point rsync at an imagined ArcaCipher host.

You can use rsync today to gather files on a machine you control. A future upload from that machine would use a validated S3-compatible tool such as rclone with crypt.

2. Prepare a local staging copy

This Unix-like shell example assumes ./source/ exists. Use a separate local staging directory with enough free space, outside the source tree. Review the dry run before copying.

mkdir -p ./backup-staging
rsync -av --dry-run ./source/ ./backup-staging/
rsync -av ./source/ ./backup-staging/

The trailing slash copies the source directory’s contents. These commands omit --delete, so files removed from the source remain in staging; changed files at the same path can still be overwritten. This is neither a snapshot nor a version history.

3. Protect the staging machine

The staging copy is readable local data. Restrict access and protect its disk. Do not copy a live database and assume it is recoverable: create an application-consistent export or use its supported backup procedure first.

rsync’s archive mode is not a guarantee that every permission, extended attribute or platform-specific detail will survive a later object-storage upload. If those details matter, use a suitable archive or backup format and test its restoration.

4. Upload and recover when available

Follow the rclone guide to configure arca-private with client-side encryption once ArcaCipher access exists. Only after a successful staging run, preview the upload:

rclone copy ./backup-staging arca-private:staging-trial --dry-run

Review it, then remove --dry-run to upload. Restore into a fresh local folder through the same crypt remote and compare the files. Do not delete your originals or staging copy until recovery has been proven. Any automation should stop if staging fails, so a partial copy is not mistaken for a successful backup.

Read the official rsync manual and general backup checklist.