Backup is the controlled process of creating, storing, and managing independent copies of data in order to ensure its recovery in case of data loss, corruption, cyberattacks, hardware failure, software errors, or human mistakes.
A backup is not merely a copy of data; it is part of a data protection strategy that defines what is saved, how often, where, for how long, and how reliably it can be restored.
What Backup Protects Against?
Properly implemented backups protect against:
- Hardware failures
Disk, RAID controller, power supply, or server failure. - Software issues
OS crashes, failed updates, database corruption, and application bugs. - Human errors
Accidental deletion, overwriting data, and incorrect configuration changes. - Cybersecurity incidents
Ransomware, destructive attacks, unauthorized access. - Operational incidents
Failed migrations, deployment errors, or infrastructure reconfiguration mistakes.
Backups do not replace high availability or redundancy; they complement them.
Backup vs Redundancy (Critical Distinction)
These terms are often confused but serve different purposes:
- Redundancy (RAID, clusters, replication)
Ensures continuity of service during component failures. - Backup
Ensures data recovery when data is already lost or corrupted.
If corrupted data is replicated or written to RAID, it is replicated instantly; only a backup allows rollback to a clean state.
Key Backup Characteristics
A professional backup system is defined by the following parameters:
1. Backup Scope
- Filesystems
- Databases
- Virtual machines
- Application-specific data
- Configuration files and metadata
Incomplete backups are one of the most common failure points.
2. Backup Frequency
- On-demand
- Scheduled (daily, hourly, etc.)
- Continuous or near-real-time (for critical data)
The frequency determines the Recovery Point Objective (RPO) – how much data loss is acceptable.
3. Backup Types
- Full backup – complete copy of all data
- Incremental backup – only changes since the last backup
- Differential backup – changes since the last full backup
- Snapshot-based backup – point-in-time state of a system or volume
In practice, combinations are used to balance speed, storage usage, and reliability.
4. Storage Location
- Same data center (fast recovery, limited protection)
- Different data center or region
- Separate infrastructure or storage system
- Offline or cold storage (for critical archives)
A backup stored on the same server is not a backup.
5. Retention Policy
- How long are they stored
- Number of restore points
- Compliance or legal requirements
Without a clear retention policy, backups either become useless or uncontrollably expensive.
Backup and Restore Are Not the Same Thing
A backup is only valuable if restoration is possible and tested.
Professional backup practice always includes:
- Regular restore tests
- Verification of data integrity
- Clear restoration procedures
- Defined Recovery Time Objective (RTO) – how quickly data must be restored.
Unverified backups create a false sense of security.
Backup in Dedicated Infrastructure
In dedicated environments, backups can be implemented with maximum control:
- Separate backup servers or storage clusters
- Isolated network paths
- Client-defined schedules and policies
- Application-aware backup logic
- Encryption at rest and in transit
This allows backups to be tailored to business logic, rather than forcing a one-size-fits-all solution.
What Backup Is Not
❌ Not high availability
❌ Not replication
❌ Not snapshots alone
❌ Not guaranteed data recovery without testing
❌ Not “set once and forget.”
Backups require ongoing monitoring and responsibility.
Business Value of Backup
For the client, backup provides:
- Protection against irreversible data loss
- Business continuity after incidents
- Confidence during updates and experiments
- Reduced financial and reputational risk
For us, backup is part of responsible infrastructure management:
We design systems so that mistakes, which are inevitable in any complex system, are always recoverable.
Our Approach to Backup
We treat backup as:
- A designed process, not an optional feature
- A negotiated responsibility (what we back up vs what the client manages)
- A critical component of stable infrastructure