SNAX/APC Configuration and Management Manual

Objects for SNAX/APC
SNAX/APC Configuration and Management Manual—138787
7-10
Object States
Object States
Objects defined for SNAX/APC are always in one of several states. The state of an
object at any given instant is important. Certain commands have no effect on an object
when it is in some states, but can affect the same object when it is in a different state.
For most objects, the state changes as commands are issued against the object. This can
be illustrated by the act of starting an LU, which causes the state to change from
STOPPED, to STARTING, to STARTED.
The state is used in several ways. For example, when the SNAX/APC subsystem
responds to a STATUS command, it always returns the state of the object. When the
SEL parameter is used in a command, it indicates that the command applies only to
objects in the specified state. The state must be valid for the specified object type or
command. For example, if the ALTER command is applied to the LU object type, the
only valid value for the SEL parameter is STOPPED.
Table 7-2
summarizes the object states as they apply to the various object types.
CONV States
The following describes the states of the CONV object.
1. The CONV object enters the STARTING state when an ALLOCATE conversation
verb or a remote ATTACH request is received.
If an ABORT TPI or STOP TPI command is received while the parent TPI object is
in the STARTING state, the CONV object ceases to exist.
Table 7-2. Object States for Each Object Type
Object State
CONV LU PROCESS PTNR-LU PTNR-MODE SESSION TPN TPI
STOPPED X * X X X
STOPPING X * X X
STARTED XXXXXXXX
STARTING XX* XXXXX
*The summary state for the PROCESS object is STARTED. A backup process can have additional operating
system process states, such as STARTED, STARTING, STOPPED, STOPPING, and SUSPENDED. Refer to
the Subsystem Control Facility (SCF) Reference Manual for more information on backup processes and object
summary states.
Note. When you issue an ABORT SESSION command or a file system error occurs,
SNAX/APC closes the underlying access method and then tries to reopen it. If the open fails,
the SNAX/APC LU and its subordinates remain in the STARTING state. (Refer to the Automatic
Error Recovery subsection.)