JBOD Pros: Pros: Pros: Pros: Concurrent Data Single loss Minimum cost sequential isolation; does not Minimum streams to single loss prevent power separate affects one access to disk other disks Cons: Susceptibility Cons: to load Data loss imbalance one failure Striping Pros: Pros: (RAID 0) Balanced Minimum cost load Minimum Potential for power better response Two-disk times, minimum throughput, and concurrency Cons: Cons: Cons: Data loss Single loss Difficult stripe after one prevents unit size failure access to choice Single loss entire array affects the entire Mirroring Pros: Pros: Pros: (RAID 1) Two data Single loss Single loss sources for and and often every read multiple multiple request (up to losses (in losses (in 100% large large Two-disk performance minimum improvement) ) are do not survivable prevent access Cons: Cons: Writes must Twice the update all cost of mirrors RAID 0 or (simplest JBOD Up to twice the power
JBOD Pros: Concurrent sequential streams to separate Cons: Susceptibility to load imbalance Pros: Data isolation; single loss affects one disk Cons: Data loss one failure Pros: Single loss does not prevent access to other disks Pros: Minimum cost Minimum power Striping (RAID 0) Two-disk minimum Pros: Balanced load Potential for better response times, throughput, and concurrency Cons: Difficult stripe unit size choice Cons: Data loss after one failure Single loss affects the entire Cons: Single loss prevents access to entire array Pros: Minimum cost Minimum power Mirroring (RAID 1) Two-disk minimum Pros: Two data sources for every read request (up to 100% performance improvement) Cons: Writes must update all mirrors (simplest Pros: Single loss and multiple losses (in large are survivable Pros: Single loss and often multiple losses (in large do not prevent access Cons: Twice the cost of RAID 0 or JBOD Up to twice the power )