Ytsejam wrote: > Now, I got a new router, so I change rrd to collect from the new router & a > new interface. > I also copy the old serial interface .rrd & .meta file and rename to the new > interface, so that I can keep the history data. > It works, but because the counter is different between old router/interface > and new one. > When rrd collect data from the new interface and update into the old .rrd > file, > it generates a huge peak!
This is a variant on the counter-reset problem. The most easy way to circumvent this is to insert some unknowns in the input. This should generate two unknown intervals. The rates are calculated by subtracting the previous value from the current one. Indeed, if you change devices (or reset the counters for that matter) you can have a problem. However, if you subtract the unknown value from the current value (which is what happens if you insert an unknown followed by the new value) you will end up with an unknown rate. time x+ 0: last time polling the old device time x+300: first time polling the new device time x+600: next time polling the new device This may generate this spike you describe (it depends on the actual counter values on both the old and the new device). The second interval will be normal again. time x+ 0: last time polling the old device time x+ 1: insert the unknown value time x+300: first time polling the new device time x+600: next time polling the new device The interval from x to x+300 will be unknown. The interval from x+300 to x+600 will be calculated correctly as both values come from the new device. HTH -- __________________________________________________________________ / [EMAIL PROTECTED] [EMAIL PROTECTED] \ | work private | | My employer is capable of speaking therefore I speak only for myself | +----------------------------------------------------------------------+ | Technical questions sent directly to me will be nuked. Use the list. | +----------------------------------------------------------------------+ | http://faq.mrtg.org/ | | http://rrdtool.eu.org --> tutorial | +----------------------------------------------------------------------+ -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
