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What it means

Most erasure-coded storage picks one coding and applies it to everything. SkyeConnex treats the coding as a decision made per upload, once the real constraints are known.

The baseline is Reed-Solomon RS(5,2) — seven shards, five data and two parity, surviving the loss of any two. That is the default and it is what most accounts run. Adaptive coding extends the range above it; it never reaches below it.

Why it is resolved after geo-policy

The provider pool a file will actually land on is not known until your jurisdictional rules have been applied. A policy that permits four vendors and a policy that permits eleven produce genuinely different durability, from identical settings.

So the coding is chosen after the pool is resolved, at upload-init, before anything is committed. Your residency policy shapes the maths rather than fighting it: a tighter jurisdiction buys wider parity instead of thinner cover.

The two guarantees

  • Durability never decreases. A generous pool does not earn a cheaper, weaker coding. Adaptation only ever widens.
  • The frame size never moves. The frame size negotiated with the client at upload-init is fixed for the upload, whatever the pool looks like. Only the parity adapts.

Sizing

Where a company enables size-based coding, small files trade cheap bytes for survivability and large files trade a slice of durability for storage efficiency — decided once at upload-init and held for the whole file. A megabyte-scale file can carry more parity than data; a multi-gigabyte archive is coded for efficiency at scale.

Ceilings are a real stop, not a hint. When no admissible coding survives the pool, the upload falls back to the baseline and the wider pool rather than silently doubling a storage bill.

Related

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