MissRate
- Hit/Miss Rate is most interesting parameter in designing and evaluating HSM configuration.
- Tape/Disk capacity Ratio
- No. of resources (SCSI lines, Disk Unit, # of Tapes)
- But since our system just started, user data (~0.2TB) is still in the disk Hierarchy.
- We assumed 90/10 Locality rule:“10% of whole data is used in 90% probability “
- In our case Disk can hold ~10% of whole capacity.MissRate = 0.1 (assumption)
MissRate