Mirroring

Mirroring is a strategy that pairs a primary chunk of one defined dbspace with an equal-sized mirror chunk.

Every write to the primary chunk is automatically accompanied by an identical write to the mirror chunk. This concept is illustrated in Figure 101. If a failure occurs on the primary chunk, mirroring enables you to read from and write to the mirror chunk until you can recover the primary chunk, all without interrupting user access to data.

Figure 101. Writing Data to Both the Primary Chunk and the Mirror Chunk

Mirroring is not supported on disks that are managed over a network. The same database server instance must manage all the chunks of a mirrored set.