Disk Mirroring

Mirroring
Standard Host Adapter
Drive 1
Drive 2
Data A
Data A
Data B
Data B
Data C
Data C
Original Data
Mirrored Data
Duplexing
Standard Host Adapter 1
Standard Host Adapter 2
Drive 1
Drive 2
Data A
Data A
Data B
Data B
Data C
Data C
Original Data
Mirrored Data

Minimum Number of Drives: 2
Strengths: Very high performance; Very high data protection; Very minimal penalty on write performance.
Weaknesses: High redundancy cost overhead; Because all data is duplicated, twice the storage capacity is required.