z/VM: CP Commands and Utilities Reference - z/VM - IBM

SET MDCACHE
later time, all links to the minidisk are dropped, then the cache eligibility of
the minidisk is determined from the directory entry for any subsequent link to
the minidisk.
ON
is valid at the SYSTEM and MDISK levels.
v The ON option at the SYSTEM level enables minidisk caching for the entire
system without changing any real device or minidisk cache settings.
v The ON option at the MDISK level enables minidisk caching for a minidisk.
Note that the real device on which the minidisk resides must be set to
DFLTON or DFLTOFF also before caching will occur. If specified without the
RECORDMDC option and record caching is enabled, record caching is
turned off for the minidisk.
OFF
is valid at the SYSTEM, RDEV, and MDISK levels.
v The OFF option at the SYSTEM level disables minidisk caching for the entire
system without changing any real device or minidisk cache settings.
v The OFF option at the RDEV level disables minidisk caching for an entire
real device. This command overrides any minidisk MDC setting set by the
MINIOPT directory control statement or the SET MDCACHE MDISK
command.
v The OFF option at the MDISK level disables minidisk caching for a minidisk.
It also turns off RECORDMDC for the minidisk if it is active.
DFLTON
is valid at the RDEV level.
v The DFLTON option enables minidisk caching for an entire real device, yet
allows the installation to disable cache eligibility for any minidisk that resides
on that device via the MINIOPT NOMDC directory control statement or the
SET MDCACHE MDISK OFF command.
DFLTOFF
is valid at the RDEV level.
v The DFLTOFF option disables cache eligibility for the entire real device, yet
allows the installation to enable cache eligibility for any minidisk that resides
on that device via the MINIOPT MDC directory control statement or the SET
MDCACHE MDISK ON command.
FLUSH
is valid at the RDEV and MDISK levels.
v The FLUSH option at the RDEV level temporarily purges the data in the
cache belonging to a real device. It does not change cache eligibility settings.
v The FLUSH option at the MDISK level temporarily purges the data in the
cache belonging to a minidisk. It does not change cache eligibility settings.
Class G users can use the SET MDCACHE FLUSH vdev-vdev command for
active minidisks defined in their directory entry.
rdev
rdev-rdev
identifies the real device numbers whose cache eligibility is to be changed.
Userid *
Userid userid
is the user ID of the virtual machine for which you want to change minidisk
cache settings. If omitted or specified as an asterisk (*), CP uses the user ID of
Chapter 2. CP Commands 1287