RAIDS: DISK ARRAYS
Arrays of small and inexpensive disks
Increase potential throughput by having many disk drives
Data is spread over multiple disk
Multiple accesses are made to several disks at a time
Reliability is lower than a single disk
But availability can be improved by adding redundant disks
(RAID)
Lost information can be reconstructed from redundant information
MTTR: mean time to repair is in the order of hours
MTTF: mean time to failure of disks is tens of years