Planning Considerations for
Tc support this environment, the device
control statement in the
should be dedicated to the
ATTACH command or DEDICATE
In the above shared
virtual machine operating systems and the
are mutually exclusive. The
The protecticn offered by the hardware reserve is lost. It is
recommended that a single path be defined in
will be dedicated to virtual machines and then shared between other
virtual machines or processors.
The device can be defined as a minidisk, on the
which begins at real cylinder
alternate path support are mutually exclusive. It should be noted that
virtual reserve/release support should not be used in this environment.
The volume being shared should not contain more than one minidisk or be
used for
processor could lock out virtual machine users or
release protection at the minidisk level, including full volume
minidisks.
machines that support
a character
directory. All subsequent links to this minidisk are subject to virtual
reserve/release processing. A software locking structure is created to
manage the reservation status by minidisk. The
then examines virtual machine channel programs and manages the reserve/
release
busy" condition in response to a virtual machine
is already reserved by another virtual machine.
released, a
users who received a
issue reserve/release CCws. However, no "device
reserved, a subsequent Diagnose request for another virtual machine is
queued until the minidisk is released, at which time the Diagnose
request will be redriven.
48