FA-72043 / Error-correcting codes / Member archive

RAID-5 skips the parity consistency check · case 03

Stripes with silent corruption are returned as valid data.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

RAID-5 left-symmetric layout on n >= 3 disks: in stripe s the parity lives on disk n-1-(s mod n) and data chunk j lives on disk (parity + 1 + j) mod n. blocks lists the stripe per disk (ints; at most one None for a failed disk). A missing block is rebuilt by XOR; with no missing block the XOR of all blocks must be 0 or the result is "parity-mismatch". Return [data chunks in logical order, parity block].

Why this case matters

Array controllers rebuild degraded stripes and must map disks to logical chunks correctly.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression [[44, 55, 172, 192, 118], 2, 5]	`[[192, 118, 44, 55], 172]`	`"parity-mismatch"`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.