Setting Cache Off for the Subsystem

SETCACHE SUBSYSTEM OFF sets normal caching off for the subsystem. The following actions occur:
  • Device caching, cache fast write, and DASD fast write stop. Device status, with respect to each of these functions, is retained and the active functions resume when subsystem caching is set on. When DASD fast write and dual copy are set on together (fast dual copy), the data is destaged from NVS to both devices.
  • Each duplex pair is set to suspended state on the first write operation to the pair. Also, any duplex pairs with out-of-synchronization cylinders are suspended after SETCACHE SUBSYSTEM OFF is issued. However, if there is no write activity to a duplex pair, and all cylinders are in synchronization, the pair is not set to suspended duplex state.
  • The Storage Control destages all modified data from cache and NVS to DASD.
Parent topic: Using SETCACHE