Data Collection

One year's worth of data for two variables (Rx and Tx bytes) requires a round-robin database (rrd) file size of 76K. If errors and discards are also collected, the rrd file size becomes 110K. The default internal values are:

A 1000-port SAN requires 110 MB for a year's worth of historical data that includes errors and discards. If there were 20 switches in this SAN with equal distribution of fabric ports, about two to three SNMP packets per switch would be sent every 5 minutes for a total of about 100 request or response SNMP packets required to monitor the data.

Flows, because of their variable counter requests, are more difficult to predict storage space requirements for. But as a rule of thumb, each extra flow adds another 76 kB.

Note     Performance Manager does not collect statistics on non-manageable and non-MDS switches. Loop devices (FL/NL) are not collected.



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