Service Manual

Fabric OS 7.4.0a Release Notes v2.0 Page 48 of 53
• If you are using the portCfgEportCredit
portCfgEportCredit portCfgEportCredit
portCfgEportCredit command, a maximum of 16 buffer credits can be configured on all
the ICL ports when all the 16 ICL ports are in the disabled state. After enabling all the ports, until the buffer
credits are available, the ports will come up with the configured buffer credits. The remaining ports will come
up in degraded mode. In case of remaining QoS-enabled ports, the ports will come up without QoS enabled. If
all the ICL ports are QoS enabled, there will only be 448 buffer credits available for 2 km distance support.
• Due to the 2 km QSFP module limitation, the link failure counter is not reliable during module or cable
removal or insertion.
Base Switch support on the 7840
FOS v7.4 enhances Virtual Fabric support on 7840 switches to include the base switch, i.e., to support XISL.
FICON users can configure E_port (ISL over FC), and VE_port (ISL over GE) in base switch. The maximum
number of logical switches supported — including the base switch — remains four. Two of the logical switches
can support CUP.
MAPS-FMS as a MAPS action (FMS CUP)
The Monitoring and Alerting Policy Suite (MAPS) is an optional storage area network (SAN) health monitor
supported on all switches running Fabric OS 7.2.0 or later. MAPS allows you to enable each switch to
constantly monitor itself for potential faults and automatically alerts you to problems before they become
costly failures.
MAPS tracks a variety of SAN fabric metrics and events. Monitoring fabric-wide events, ports, and
environmental parameters enables early fault detection and isolation as well as performance measurements.
MAPS provides the following set of predefined monitoring policies that allow you to immediately use MAPS on
activation:
• dflt_conservative_policy
• dflt_moderate_policy
• dflt_aggressive_policy
It is recommended that all IBM z Systems customers enable MAPS after upgrading to Fabric OS version
supporting MAPS and use the default aggressive policy (dflt_aggressive_policy). This policy contains rules with
very strict thresholds.
FOS v7.4 introduces FICON notification as a new action that enables MAPS events to be sent to FMS with
detailed event information upon rule violations. FMS CUP can translate these MAPS events into FICON-specific
Health Summary Check reports via the z/OS I/O Health Checker. In order to send the MAPS triggered events
notification, MAPS supports the new action configurable at rule and maps global action level.
The rules with FICON notification action are part of all three default policies such as dflt_aggressive_policy,
dflt_moderate_policy and dflt_conservative_policy. In the active policy, if FICON notification action is
configured for any triggered events, then MAPS sends the notification to FMS with event information. The
following information are send to FMS:
 Triggered event rule name
 Object and its type on which the event was triggered
 Severity of the event
 Condition on which the event was triggered
 Monitoring service details and the measured value
Dynamic Load Sharing-E_Port balancing
With this enhancement, when multiple paths to a domain exist, routing policy would assign routes so that the
bandwidth demands from source ports are evenly distributed among all E_Ports.
E_port balance priority allows you to balance the E_port load. You can enable the E_port balance priority
feature from Web Tools. When you enable the E_port balance priority feature, the E_Port load will be even
across all the E_Ports of same domain during the topology change. You can select Rebalance
Rebalance Rebalance
Rebalance or Rebalance
Rebalance Rebalance
Rebalance