Question
You have a server that runs Windows Server and contains 10 physical disks.
You plan to implement storage spaces that will use the disks.
You are evaluating whether to configure the following options:
• A two-way mirror
• A parity storage layout
What is the maximum number of disks that can fail without data loss for each option? To answer, select the appropriate options in the answer area.
NOTE: Each correct selection is worth one point.
Explanation
Two-way mirror: 1 — A two-way mirror in Storage Spaces keeps two copies of every slab of data on separate physical disks, so any single disk can fail and a complete second copy of all data remains available. Losing two disks could take out both copies of the same slab, so 1 is the maximum guaranteed fault tolerance; only a three-way mirror (three copies, minimum five disks) survives two simultaneous failures.
Parity storage layout: 2 — With 10 physical disks the server meets the seven-disk minimum for dual parity, which writes two independent parity symbols per stripe and therefore tolerates the loss of two disks without data loss while still being far more capacity-efficient than mirroring. Single parity would only survive 1 failure, but the disk count here allows the dual-parity layout, so 2 is the maximum for a parity configuration on this server.
