SETCACHE
SETCACHE Parameters
Required Parameters
FILE(ddname)|{VOLUME(volser)+UNIT(unittype)|UNITNUMBER(devid)} specifies the volume of a unit within the subsystem.
FILE(ddname) specifies the name of a DD statement that identifies the device type and volume of a unit within the subsystem. For ddname, substitute the name of the DD statement identifying the device type.
VOLUME(volser) specifies the volume serial number of a volume within the subsystem.
Abbreviation:
VOL
UNIT(unittype) specifies the unit type of the subsystem.
UNITNUMBER(devid) is the MVS device number. The UNITNUMBER parameter is only accepted with the following:
DEVICE ON or OFF
SUBSYSTEM OFF
NVS OFF
DASDFASTWRITE ON or OFF or PENDINGOFF
DISCARDPINNED
REINITIALIZE
RESETTOSIMPLEX
CACHEFASTWRITE
Abbreviation:
UNUM
Note:
The UNITNUMBER parameter cannot be used for an online device in the “Intervention Required” state.
Optional Parameters
DEVICE|SUBSYSTEM|NVS|DASDFASTWRITE|CACHEFASTWRITE
specifies whether the command pertains to caching for a specific device or subsystem caching, nonvolatile storage, DASD fast write to a specific device, or cache fast write access for the subsystem.
DEVICE
specifies that access to the cache for a particular device is allowed or prohibited.
Abbreviation:
DEV
Note:
1.
DEVICE OFF is not supported for the ESS.
2.
DEVICE ON or OFF can be issued to an offline device by using the
UNITNUMBER parameter.
SUBSYSTEM
specifies that access to cache for the subsystem is allowed or prohibited.
Abbreviation:
SUBSYS or SSYS
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Note:
1.
SUBSYSTEM OFF is not supported for the ESS.
2.
SUBSYSTEM OFF can be issued to an offline device by using the
UNITNUMBER parameter.
3.
READ access authority to the RACF FACILITY class resource
STGADMIN.IDC.SETCACHE.SUBSYSTEM is required to use the
SUBSYSTEM parameter.
Attention:
When cache operation is restored, SETCACHE
RESETTODUPLEX must be issued for each suspended duplex pair in the subsystem.
NVS
specifies that access to the nonvolatile storage is allowed or prohibited.
Note:
1.
NVS OFF is not supported for the ESS.
2.
NVS OFF can be issued to an offline device by using the
UNITNUMBER parameter.
Note:
DASDFASTWRITE
specifies that DASD fast write to a particular device is allowed or prohibited.
Abbreviation:
DFW or DASDFW
Note:
1.
DASDFASTWRITE OFF is not supported for the ESS.
2.
DASDFASTWRITE ON or OFF or PENDINGOFF can be issued to an offline device by using the UNITNUMBER parameter.
CACHEFASTWRITE
specifies that cache fast write for the subsystem is allowed or prohibited.
Abbreviation:
CFW or CACHEFW
ON|OFF|PENDINGOFF
specifies whether access is allowed or prohibited.
ON
specifies that access is allowed.
OFF
specifies that access is prohibited.
Note:
Setting cache on or off for the subsystem and setting cache on or off for a device are independent operations. That is, cache can be set on or off for individual devices whether the cache is on or off for the subsystem.
However, if the cache is set off for the subsystem, setting cache on for an individual device has no effect until the cache is set on for the subsystem.
PENDINGOFF
specifies a recovery command to allow cache or DASD fast write to a particular device to be set off when cache or DASD fast write is in pending state.
Abbreviation:
PEND.
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SETCACHE
Note:
1.
This parameter should only be used as a last resort because no destage occurs and data could be lost.
2.
The PENDINGOFF parameter must be used with either SUBSYSTEM or
DASDFASTWRITE, and is accepted only if SUBSYSTEM OFF or
DASDFASTWRITE OFF failed. That is, when the PENDINGOFF parameter is used with DASDFASTWRITE, the device must be in the
DEACTIVATION PENDING state. When the PENDINGOFF parameter is used with SUBSYSTEM, the subsystem must be in the
DEACTIVATION FAILED state (see LISTDATA STATUS). Otherwise, the command is rejected.
3.
PENDINGOFF is not available for NVS. If NVS OFF does not obtain the desired result, issue a DASDFASTWRITE PENDINGOFF to each device where DASD fast write is in a deactivation pending state. NVS
OFF should then work.
SUBCHSET(n)
Specifies the subchannel set number from 0 to 3 that the device number specified with the UNITNUMBEr resides in. Valid with the
CACHEFASTWRITE optional parameter when the UNITNUMBER parameter is used.
Special Purpose Optional Parameters
The following parameters are not to be issued concurrently with the optional parameters described previously, or with each other, unless otherwise noted.
DISCARDPINNED|DESTAGE|REINITIALIZE|SETSECONDARY(
devid)|
SUSPENDPRIMARY|SUSPENDSECONDARY|RESETTODUPLEX|
REESTABLISHDUPLEX(
devid)|RESETTOSIMPLEX specifies operations pertaining to dual copy.
DISCARDPINNED
specifies that all pinned cache fast write data and DASD fast write data for the specified volume is discarded.
Abbreviation:
DPIN.
Note:
DISCARDPINNED can be issued to an offline device by using the
UNITNUMBER parameter.
DESTAGE
specifies that a destage to DASD of all modified tracks in the cache and NVS is to be scheduled.
Abbreviation:
DESTG
REINITIALIZE
causes a cached Storage Control subsystem to unconditionally establish or reestablish all caching status on the subsystem status devices. (This is a reconfiguration of the subsystem, setting all caching status to its default values.) REINITIALIZE requires the use of the UNITNUMBER parameter, because all devices must be offline before the command is executed.
REINITIALIZE also resets all CCAs and DDCs to the initial installation values
(direct translation).
Abbreviation:
RINIT or REINIT
Note:
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1.
The REINITIALIZE parameter terminates dual copy logical volumes
(duplex pairs).
2.
Ensure that other operating systems are not accessing the target subsystem before using the REINITIALIZE command.
3.
The REINITIALIZE parameter causes pinned data to be lost.
SETSECONDARY(devid) specifies that a dual copy (duplex) pair is to be established. The secondary volume must be offline and is identified by its devid (devid is the MVS device number). DASD fast write and caching status of the primary volume are maintained for the duplex pair.
Abbreviation:
SSEC
Note:
1.
This parameter is not supported for the ESS.
2.
With this parameter, the JCL JOB statement should include 'TIME=1440'.
3.
This parameter may be used in conjunction with COPY (with or without
PACE) or NOCOPY.
4.
During the process of establishing a duplex pair, caching for the primary volume is temporarily deactivated.
5.
When you use dual copy to migrate from 3390 devices to RAMAC devices, an invalid format 4 DSCB is created on the target device. Use ICKDSF to fix the format 4 DSCB. See your IBM representative for the latest service level of ICKDSF that provides this function.
Device level caching, for both primary and secondary devices, is set to off to force data destaging. It is set back to on, automatically by software, after the dual copy operation completes.
The software can be overridden by IDCAMS allowing cache to be set on after the establishment of a duplex pair has been initiated (verify with a DEVSERV command that status is pending for primary device before setting device cache to on).
SUSPENDPRIMARY
suspends the primary volume of a duplex pair. The subsystem swaps the primary and secondary volumes of the duplex pair. The suspended device is the secondary address. DASD fast write status and caching status are maintained.
Abbreviation:
SUSPRI or SPPRI
Note:
This parameter is not supported for the ESS.
SUSPENDSECONDARY
suspends the secondary volume of a duplex pair. DASD fast write status and caching status are maintained.
Abbreviation:
SUSSEC or SPSEC
Note:
This parameter is not supported for the ESS.
RESETTODUPLEX
establishes a duplex pair from a suspended duplex pair. The subsystem always attempts to match channel connection addresses (CCAs) and director-to-device connection (DDC) addresses, and swaps the devices after synchronization if a swap would result in a match. If the pair is swapped, all data in the cache is invalidated. DASD fast write status and caching status are maintained.
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Abbreviation:
RESETDUP or REDUP
Note:
1.
This parameter is not supported for the ESS.
2.
With this parameter, the JCL JOB statement should include 'TIME=1440'.
3.
COPY and PACE can be used in conjunction with this parameter.
REESTABLISHDUPLEX(devid) reestablishes a duplex pair from the primary volume in a suspended duplex pair and the user-specified alternate device. DASD fast write status and caching status are maintained. Abbreviation: REEST
Note:
1.
This parameter is not supported for the ESS.
2.
With this parameter, the JCL JOB statement should include 'TIME=1440'.
3.
COPY and PACE can be used in conjunction with this parameter.
RESETTOSIMPLEX
terminates a duplex pair. When the volumes are changed from a duplex pair to simplex volumes, the old primary volume retains the DASD fast write and the device caching status of the duplex pair. For the old secondary volume, DASD fast write becomes inactive and device caching becomes active (reverts to default status). Abbreviation: RESETSIM or RESIM
Note:
1.
This parameter is not supported for the ESS.
2.
RESETTOSIMPLEX can be issued to an offline device by using the
UNITNUMBER parameter.
COPY|NOCOPY
specifies whether or not the Storage Control is to copy the primary volume onto the secondary volume when establishing a duplex pair (used only with the SETSECONDARY parameter).
COPY
specifies that the Storage Control is to copy the primary volume onto the secondary when establishing a duplex pair (SETSECONDARY). (Copy can be used with the RESETTODUPLEX and the REESTABLISHDUPLEX parameters.)
Note:
Specify the COPY parameter, except for pairs of primary and secondary volumes that have just been initialized by ICKDSF using the same initialization parameters.
NOCOPY
specifies that the primary and secondary volumes are identical and the
Storage Control does not need to copy the primary volume onto the secondary to establish the duplex pair (used only with SETSECONDARY; cannot be used with REESTABLISHDUPLEX or RESETTODUPLEX).
Note:
1.
The subsystem keeps an indication that the duplex pair was established using an internal copy. If an error results because the two volumes are not identical, this indicator is checked. The message given as a result of
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