Simple Backups¶

Compare first, back up second, then verify with the same comparison command.

zelta match tank/data backup@storage.example.com:tank/Backups/data
zelta backup tank/data backup@storage.example.com:tank/Backups/data
zelta match tank/data backup@storage.example.com:tank/Backups/data

zelta backup creates snapshots when needed, detects the best incremental stream, and creates read-only backup datasets by default. Run the same command again later to update incrementally. If nothing changed on the source, Zelta will not create a pointless new snapshot.

For flags and full option lists, see zelta-backup(8) and zelta-options(7).

Defaults Worth Knowing¶

Most backups need only the two endpoints and no switches:

These target defaults avoid accidental overlays and keep replicas safe to receive again. Details live in the man page; the short version is: backups should not surprise you at mount time.

Narrow What You Send¶

Use --include and --exclude to narrow dataset or snapshot selection. Snapshot patterns begin with @.

# Skip hourly snapshots on the target stream
zelta backup --exclude '@hourly_*' tank/data backup:tank/Backups/data

# Only a critical child and daily snapshots
zelta backup --include '/critical,@daily_*' tank/data backup:tank/Backups/data

# Name new snapshots on the source
zelta backup --snap-prefix=daily --include='@daily*' \
  alpha:ark/ds vault:vat/ds

Global depth, include, and exclude filters work across Zelta commands. When a ZFS send flag is set explicitly, it overrides Zelta defaults for that send.

Optional Send Bookmarks¶

--bookmark creates a ZFS bookmark for the latest successfully sent snapshot, tagged with useful host context. It is off by default.

zelta backup --bookmark tank/data backup:tank/Backups/data

Bookmarks help incremental continuity and point-of-use telemetry. The backup user needs the ZFS bookmark permission; see ZFS Allow Delegation.

Intermediate Snapshots¶

By default, intermediate snapshots between the match and the latest source snapshot are included so the target keeps a usable history. That costs transfer size and target space.

If you only need the latest common chain for a fast update, filter with snapshot patterns or use intermediate-skip settings documented in zelta-options(7) (SEND_INTR / related flags). Prefer filters when you still want named history on the target (for example only @daily*).

Schedule Or Policy¶

For recurring backups, either schedule direct commands with cron:

0 */6 * * * zelta backup tank/data backup@storage:tank/Backups/data

or move repeated jobs into Policy-Based Automatic Backups.

For active-passive pairs, see Zelta Twin and Failover Workflows.