HP StorageWorks 2.140 Director Switch - Manual (Page 81)

Director Element Manager user guide 81
Operational statistics
The following describes the operational statistics that display for a selected port:
• Offline sequences Rx—The number of off line sequences that the port has received.
• Offline sequences Tx—The number of off line sequences that the port has transmitted.
• Link resets—The number of link reset protocol frames received/transmitted by this port from/to
the attached device. The director transmits a link reset to initiate the link reset protocol or recover
from a link timeout. This occurs normally to establish BB_Credit or on any port in order to
recover lost BB_Credit. The director receives a link reset from an attached device if the device
wishes to initiate the link reset or recover from a link timeout.
Traffic statistics with receive and transmit values
This section describes the types of traffic statistics that display for a selected port:
• Link Utilization % Rx and Link Utilization %Tx—Separate values for transmit (Tx) and receive (Rx)
link utilization. The larger of these two values is displayed on the bar graph.
The current link utilization for the port is expressed as a percentage. Each port can transmit or
receive data at 100 megabytes (MB) per second if the port is set to 1 Gig. If the port is set to
2 Gig, the port can transmit or receive data at 200 MB per second.This statistic shows the
percentage of the maximum link utilization currently being used. Link utilization is calculated over
one-second intervals. The maximum link utilization is 100%.
• Frames Rx—The number of frames that the port has received.
• Frames Tx—The number of frames that the port has transmitted.
• Four byte words Rx—The number of words that the port has received.
• Four byte words Tx—The number of words that the port has transmitted.
• Flows rerouted from ISL—Indicates whether the optional Open Trunking feature is installed or
not. A value will only display if Open Trunking is installed, the port is connected to an ISL, and
flows are being rerouted. This is the number of Fibre Channel traffic flows that have been
rerouted from this ISL to another ISL due to congestion.
• Flows rerouted to ISL—Indicates whether the optional Open Trunking feature is installed or not.
A value will only display if Open Trunking is installed, the port is connected to an ISL, and flows
are being rerouted. This will be the number of Fibre Channel traffic flows that have been
rerouted to this ISL from another ISL due to congestion.
Troubleshooting tips
As a general rule, you should clear all counts after the system is stabilized. When looking at the
Performance view, roughly keep track of the time interval when errors accumulate to judge the
presence and severity of a problem. Also, recognize that a link recovery hierarchy is implemented in
Fibre Channel to handle some level of “expected anomalies.” In general, you need only be
concerned with error counts that increment very quickly.