QOS FEATURE KNOBS

Described are various quality of service (QOS) parameters that may be used in characterizing device behavior in connection with a cache. A Partition parameter indicates which portions of available cache may used with data of an associated device. A Survival parameter indicates how long data of an associate device should remain in cache after use. A Linearity parameter indicates a likelihood factor that subsequent data tracks may be used such that this parameter may be used in determining whether to prefetch data. A Flush parameter indicates how long data should remain in cache after a write pending slot is returned to cache after being written out to the actual device. The QOS parameters may be included in configuration data. The QOS parameter values may be read and/or modified.