| Description | Each entry contains information specific to a current
Fabric lock set up by a particular 'managing' switch on a
particular Fabric. The 'managing switch' is identified by
values of fcmInstanceIndex and fcmSwitchIndex.
Server sessions for several different types of servers
are defined in FC-GS-5. The behavior of a server with
respect to commands received within a server session is
specified for each type of server. For some types,
parameter changes can only be made within the context of a
session, and the setting up of a session requires that the
Fabric be locked. A Fabric is locked by one switch, called
the 'managing' switch, sending Acquire Change Authorization
(ACA) requests to all other switches in the Fabric.
For other applications, a Fabric lock is established by the
'managing' switch sending Enhanced Acquire Change
Authorization (EACA) requests to other switches in the
Fabric. Each EACA request includes an Application_ID
value to identify the application requesting the lock.
For the benefit of this MIB module, a distinct value of
Application_ID has also been assigned/reserved (see
ANSI INCITS T11/06-679v0, titled 'FC-SW-5 Letter to
T11.5') as a means of distinguishing locks established via
Acquire Change Authorization (ACA) requests. This
additional assignment allows an Application_ID to be used to
uniquely identify any active lock amongst all those
established by either an EACA or an ACA.
Whenever a Fabric is locked, by the sending of either an ACA
or an EACA, a row gets created in the representation of this
table for the 'managing' switch.
In order to process SNMP SetRequests that make parameter
changes for the relevant types of servers (e.g., to the
Zoning Database), the SNMP agent must get serialized access
to the Fabric (for the relevant type of management data),
i.e., the Fabric must be locked by creating an entry in
this table via an SNMP SetRequest. Creating an entry in
this table via an SNMP SetRequest causes an ACA or an EACA
to be sent to all other switches in the Fabric. The value
of t11FLockApplicationID for such an entry determines
whether an ACA or an EACA is sent.
If an entry in this table is created by an SNMP SetRequest,
the value of the t11FLockInitiatorType object in that entry
will normally be 'snmp'. A row for which the value of
t11FLockInitiatorType is not 'snmp' cannot be modified
via SNMP. In particular, it cannot be deleted via
t11FLockRowStatus. Note that it's possible for a row to be
created by an SNMP SetRequest, but for the setup of the lock
to fail, and immediately thereafter be replaced by a lock
successfully set up by some other means; in such a case, the
value of t11FLockInitiatorType would change as and when the
lock was set up by the other means, and so the row could
not thereafter be deleted via t11FLockRowStatus.
FC-GS-5 mentions various error situations in which a
Fabric lock is released so as to avoid a deadlock. In
such situations, the agent removes the corresponding row
in this table as and when the lock is released. This can
happen for all values of t11FLockInitiatorType. |