Mirrored protection is beneficial if you have a multibus server or a server with a large single bus. A greater number of disk units provides more opportunity for failure and increased recovery time. Mirrored protection is local to a single server and is distinct from cross-site mirroring or geographic mirroring. Mirrored protection works to prevent outage on the server by keeping a second copy of the data on a mirrored disk unit. If one disk unit fails, the server relies on the mirrored disk unit.