SETCACHE

You can use the SETCACHE command to:

Make cache available or unavailable to the subsystem for caching operations
Make an addressed device (actuator) eligible or ineligible for caching operations
Make cache unavailable to the subsystem when cache is in pending state
Make nonvolatile storage (NVS) available or unavailable to the subsystem
Activate or deactivate DASD fast write for a device
Make DASD fast write unavailable for a device when DASD fast write is in pending state
Make cache fast write access available or unavailable to the subsystem
Schedule DASD writes for all modified data in cache and NVS (destage modified data)
Discard pinned data for a device in cache and NVS
Establish a duplex pair
Establish a duplex pair from an existing suspended duplex pair
Reestablish a duplex pair from the primary volume of a suspended duplex pair and an alternate device
Reset a duplex pair to two simplex volumes
Suspend the primary or secondary volume of a duplex pair
Reinitialize the subsystem, setting all subsystem and device status to the Storage Control's initial installation default values

The format of the SETCACHE command is:

Command	Parameters
SETCACHE	{FILE(ddname)\|{VOLUME(volser)+
	UNIT(unittype)}\|
	UNITNUMBER(devid)}
	[DEVICE\|SUBSYSTEM\|NVS\|DASDFASTWRITE\|CACHEFASTWRITE]
	[ON\|OFF\|PENDINGOFF]
	SUBCHSET(n)
	[DISCARDPINNED\|DESTAGE\|REINITIALIZE\|
	SETSECONDARY(devid)\|SUSPENDPRIMARY\|
	SUSPENDSECONDARY\|RESETTODUPLEX\|
	REESTABLISHDUPLEX(devid)\|RESETTOSIMPLEX]
	[COPY\|NOCOPY]
	[PACE(n)]

Note:

The IBM® Enterprise Storage Server® (ESS) cache/DFW is on by default and you are not allowed to modify it. In addition, the ESS does not support the dual-copy function. Any SETCACHE command issued for the ESS that attempts to modify the cache/DFW or use dual-copy function will be rejected.
When the SETCACHE command parameter SETSECONDARY, RESETTODUPLEX, or REESTABLISHDUPLEX is specified, the JCL JOB statement should include the parameter 'TIME=1440' because the IDCAMS step will very likely exceed the execution time allowed by the installation time limit.
The SETCACHE command and the DISCARDPINNED, PENDINGOFF, REINITIALIZE, and SUBSYSTEM parameters may be protected by using the System Authorization Facility (SAF).