Brocade Fabric OS Command Reference Manual v6.2.0 (53-1001186-01, April 2009)

486 Fabric OS Command Reference
53-1001186-01
pathInfo
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In Port The port on which the switch receives frames. For hop 0, this is source_port.
For bladed systems and ports above 256, this parameter is the port index;
otherwise, it is the port area.
Domain ID The domain ID of the switch.
Name The name of the switch.
Out Port The output port that the frames take to reach the next hop. For the last hop,
this is destination_port. For bladed systems and ports above 256, this
parameter is the port index; otherwise, it is the port area.
BW The bandwidth of the output interswitch link (ISL), in Gbps. This parameter
does not apply to the embedded port. If the bandwidth is zero, it is displayed
as 1 Gbps. For logical interswitch links (LISL) ports, the bandwidth displays as
8 Gbps, the maximum bandwidth on hardware platforms on which LISLs can
be formed. In cases where the LISL bandwidth is zero, pathInfo displays a
bandwidth of 4 Gbps.
Cost The cost of the output link used by the fabric shortest path first (FSPF) routing
protocol. This parameter applies only if the output link is recognized by FSPF.
You can request more detailed statistics for each hop in addition to the routing information. These
statistics are presented for the input and output ports for both receive and transmit modes. You
can select basic or extended statistics or both when running pathInfo in interactive mode. Statistics
are not reported for the embedded port. Some throughput values are reported in multiple time
intervals, to describe both current path utilization and the average throughput over a larger period
of time.
To collect these statistics, this command uses a special pathInfo frame that is sent hop-by-hop
from the source switch to the destination switch. To prevent such a frame to loop forever if an error
occurs, a maximum number of hops for the frame to traverse is enforced. The hop count includes
all hops in the direct path from source to destination, and also all the hops in the reverse path, if
the tracing of the reverse path is requested. The default value for the maximum hop count is 25.
Basic statistics Basic statistics report parameters that may indicate ISL congestion along the
path. They include the following:
B/s Bytes per second received or transmitted. This value is reported for multiple
time periods displayed in parentheses.
Txcrdz The length of time, in milliseconds, that the port was unable to transmit
frames because the transmit BB credit was zero. The purpose of this statistic
is to detect congestion or a slow drain device. This parameter is sampled at 1
millisecond intervals, and the counter is incremented if the condition is true.
Each sample represents 1 ms of time with zero Tx BB Credit. An increment of
this counter means that the frames could not be sent to the attached device
for 1 ms, indicating degraded performance. This value reports for multiple
time periods, displayed in parentheses. Note that other commands, such as
portStatsShow, may express this value in units other than milliseconds.
Extended statistics
Extended statistics report variables of general interest. They include the
following:
F/s The number of frames received or transmitted per second. This value is
reported for multiple time periods, displayed in parentheses.