Guide

How to check a synthetic full backup

A synthetic full primarily stresses the backup repository, so we must distinguish source, chain and target storage.

⌚ About 2 min read
View my favorites
Backup Advanced. 20 min

A synthetic full primarily stresses the backup repository, so we must distinguish source, chain and target storage.

Avant de commencer : adaptez toujours les commandes et manipulations à votre environnement. Sur un système de production, prévoyez une backup ou un retour arrière lorsque l’action peut modifier la configuration.

Étapes à suivre

  1. 1

    Read the exact error.

    Identify the job phase.

  2. 2

    Control space.

    Include temporary need and margin.

  3. 3

    Check I/O-O-O-O-O.

    Latency and mistakes.

  4. 4

    Check the string.

    Use the available health check features.

À retenir

  • Do not delete the last valid full.
  • A backup full active can greatly increase the source/network load.
Technical deep dive

Backup: chain, immutability and capacity must be calculated together

Technical checkpoints

  • A synthetic full rebuilds a full from data already in the repository; it therefore depends on chain integrity and storage performance.
  • Immutability must cover the retention window and enough time to hold fulls/incrementals without early deletion.
  • Production capacity, change rate, compression/deduplication and growth headroom must be included in sizing.

Simple sizing

Start with protected data × change rate × restore points, then apply measured real ratios and headroom.

Capacity ≈ usable full + Σ(incrementals) + operational headroom + growth

Topic-specific pitfalls

  • Sizing only from the last full often underestimates immutable retention.
  • A successful synthetic full is not proof of restore capability; perform restore tests.

How to validate

  • The chain passes health checks and a restore test succeeds.
  • Remaining capacity covers immutable retention and forecast growth without a saturation window.
♡ 0