- Backup is often underestimated; common pitfalls include flawed techniques, untested backups, and confusion with RAID.
- Cloud providers operate on a shared responsibility model; users are ultimately responsible for backing up their data.
- A proper backup philosophy: data must be restorable quickly, in an open format, and consistent.
- Data loss can occur from fires, floods, earthquakes, ransomware, and human errors.
- A backup is not a simple copy; copying live database files is useless without a proper dump.
- Backup planning starts with questions about risk tolerance, critical data, acceptable downtime, and storage space.
- The safest backup is stored off-site, but this introduces challenges of space and bandwidth.
- Choose between full disk backup (complete recovery but may require downtime) and individual file backup (granular, portable, but needs snapshots for consistency).
- Snapshots are essential for consistency; methods include native filesystem snapshots (ZFS, Btrfs), LVM, and DattoBD.
- Prefer pull-based backups where a central server initiates connections; ensure the backup server is hardened and maintains its own snapshots for security.
- Good backup system features: instant recovery, external storage, security, efficient space management (compression, deduplication), and minimal invasiveness.