Cisco MDS 9000 Series Configuration Manual page 172

Information About Congestion Detection
• Cumulative count—Indicates the time the interface counters were last cleared, using the show
• Count in percent—Indicates when the credits are unable to transmit for the last 1 second, 1 minute,
• Graphical representation of the count for the last 60 seconds, 60 minutes, and 72 hours—In FCoE,
• On-Board Failure Log (OBFL)—An entry in the OBFL when a port accumulates 100 ms or more
In the following example, the show interface counters command output displays the data "1104349910
2.5 us TxWait due to pause frames (VL3)." This data is cumulative from the time when the counters
were last cleared or from the time when the module first came up. In this example, TxWait is incremented
1104349910 times. This data converted to seconds is (1104349910 * 2.5) / 1000000 = 2760.874 seconds.
VFC was unable to transmit for 2760.874 seconds.
In the following example, the show interface counters command output shows the data "205484298144
2.5 us RxWait due to PFC Pause frames (VL3)." This data is cumulative from the time the counters were
last cleared or from the time when the module first came up. In the example, RxWait is incremented
205484298144 times. This data converted to seconds is (205484298144 * 2.5) / 1000000 = 513710.745
seconds. VFC was unable to receive for 513710.745 seconds.
The following example also shows the percentage of time that the VFC was paused in each direction
over the last 1 second, 1 minute, 1 hour, and 72 hours. For TxWait, this is the percentage of time that
the VFC received PFC pauses. For RxWait, this is the percentage of time that the VFC was sending pause
frames preventing the other side from transmitting. In this example, in the last one minute the VFC was
prevented from transmitting (TxWait) 33% of the time (20 seconds).
switch# show interface vfc-po540 counters
vfc-po540
Percentage pause in TxWait per VL3
Percentage pause in RxWait per VL3
• Tx-credit-not-available or rx-credit-not-available (Fibre Channel only)—Tx-credit-not-available or
rx-credit-not-available is a counter that increments by 1 when a port is at zero transmit credits for 100
ms consecutively. This incrementation happens by a software process. Tx-credit-not-available information
is available using the show logging onboard error-stats command and also available using the show
system internal snmp credit-not-available command. Also, port monitor can generate
tx-credit-not-available or rx-credit-not-available alerts.
The show logging onboard error-stats command records various counters when the counters change
value. When the value of a counter changes, the current value is recorded along with the date and time.
Cisco MDS 9000 Series Interfaces Configuration Guide, Release 8.x
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interface counters and show interface counters detailed commands.
1 hour, and 72 hours, using the show interface counters and show interface counters detailed
commands.
the count is displayed using the show hardware internal rxwait-history command.
RxWait in a 20-second interval. This entry is displayed using the show logging onboard rxwait
command.
1571394073 fcoe in packets
3322884900540 fcoe in octets
79445277 fcoe out packets
69006091691 fcoe out octets
1104349910 2.5 us TxWait due to pause frames (VL3)
205484298144 2.5 us RxWait due to pause frames (VL3)
0 Tx frames with pause opcode (VL3)
3302000 Rx frames with pause opcode (VL3)
Congestion Detection, Avoidance, and Isolation
for last 1s/1m/1h/72h: 0%/33%/0%/0%
for last 1s/1m/1h/72h: 0%/0%/0%/30%