07 — Backup Specification

From the Burrow™ specification set.

07 — Backup Specification

Purpose

Maintain recoverable secondary copies and prove their integrity.

Backup vs Sync

iCloud and OneDrive synchronization alone do not satisfy the backup model.

Backup Job

A job contains:

  • name;
  • enabled state;
  • one or more source roots/collections;
  • destination;
  • schedule policy (future);
  • inclusion/exclusion rules;
  • version/retention policy;
  • verification policy.

Initial Target

The user's portable external drive is the primary first backup destination.

Modes

Initial recommended mode: incremental file backup.

Future:

  • versioned retention;
  • snapshots where supported;
  • secondary cloud backup provider.

Copy Workflow

  1. validate source;
  2. validate correct destination volume identity;
  3. compare inventory;
  4. calculate copy plan;
  5. present plan/dry run;
  6. copy changed/new files;
  7. verify;
  8. record run;
  9. never delete source because a backup succeeded.

Destination deletion/mirroring should not be introduced casually; backup is safer when source deletions do not automatically erase recovery copies.

Verification

Levels:

  • metadata verification;
  • size verification;
  • full hash verification.

Critical collections should support full verification.

Backup Health

Derived states:

  • HEALTHY
  • STALE
  • DESTINATION_OFFLINE
  • PARTIAL
  • VERIFY_FAILED
  • NEVER_RUN
  • UNKNOWN

Health considers:

  • last successful run;
  • last verified run;
  • configured freshness threshold;
  • destination availability;
  • errors;
  • unprotected changes since last run.

Collections

Examples:

  • Personal Documents
  • Development
  • Photos
  • Financial
  • Archive

The user chooses collection membership and protection policy.

Retention

Do not implement destructive retention in the first backup release. Preserve previous backup copies until retention behavior is explicitly designed and approved.

Portable Drive Identity

Never assume /Volumes/MySSD is the correct destination merely because the name matches. Validate stable volume identity.

Reporting

Each run records:

  • started/completed;
  • files considered;
  • copied/skipped/failed;
  • bytes copied;
  • verification results;
  • source/destination;
  • error summary.