HP StorageWorks MSA 2/8 HP StorageWorks Fabric OS 3.X Document Addendum (AA-RW - Page 185
pathinfo, Txcrdz, Words, Frames, Errors, in addition to those for the direct path.
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Fabric OS reference guide For each hop, statistics are divided into basic and extended. They are reported below the routing information, separated into input port statistics and output port statistics. For each port, they are further separated into transmit and receive statistics. Statistics are not reported for the embedded port. Some values are measured over multiple time intervals. For example, the output line utilization in bytes per second is calculated over both a 1-second period and over a 64-second period. This gives an idea of both the current line utilization and the utilization over a longer period of time. The time interval is reported in parenthesis after the value's description. Maximum hop count The pathinfo command uses a special frame that is sent hop-by-hop from the source switch to the destination switch, collecting routing and statistics information at every hop. To prevent such a frame from looping forever if an error occurs, a maximum number of hops for the frame to hop 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 tracing of the reverse path is requested. The default value for the maximum hop count is 25. Basic statistics Basic statistics report variables that give an indication of ISL congestion along the path. They consist of the following: B/s Bytes per second Txcrdz The length of time, in milliseconds, that the port was prevented from transmitting frames due to lack of buffer-to-buffer credit. It is an indication of downstream congestion. Other commands, such as portstatsshow, can express this value in units other than milliseconds. Extended statistics Extended statistics report variables are: F/s Frames per second Words Total number of 4-byte Fibre Channel words Frames Total number of frames Errors Total number of errors that might cause a frame not to be received correctly. This includes CRC errors, bad EOF errors, frame truncated errors, frame too short errors, and encoding errors inside a frame. Reverse path The path from port A on switch X to port B on switch Y might be different from the path from port B to port A. The difference could be in the links traversed between the same sequence of switches, or the reverse path might even involve different switches. The trace reverse path option allows the user to determine both routing and statistics information for the reverse path, in addition to those for the direct path. Fabric OS 3.x Document Addendum 185