No, setting maximum values for the counters is not a complete solution. If the counters get reset when the value of the counter is high, you will get a wrap that produces a wrong result that is also less than the maximum you set and thus will be recorded as a value. You still get wrong data in your database.
I went with the DERIVE data type. You miss one entry when there is a counter wrap, which for me is better than having a wrong entry. I put quite a bit of testing and thought in to this, and DERIVE is definitly the best for my data. -----Original Message----- From: Michael Wells [mailto:[EMAIL PROTECTED] Sent: Saturday, 18 August 2001 7:03 AM To: RRD users Subject: [rrd-users] Re: Graphs wrong after reboot - samples included Hi, Your description highlighted the problem with my graphs. The affected RRDs with counters in them have been adjusted to have proper limits (solution number 2), and the problem has now vanished. I've also made my .png images into, erm, PNGs. ;-) Here is my updated RRD definition. This is a 100Mb/s NIC. #/bin/sh rrdtool create rl0.rrd \ DS:input:COUNTER:3600:0:12500000 \ DS:output:COUNTER:3600:0:12500000 \ RRA:AVERAGE:0.5:1:600 \ RRA:AVERAGE:0.5:6:700 \ RRA:AVERAGE:0.5:24:775 \ RRA:AVERAGE:0.5:288:797 \ RRA:MAX:0.5:1:600 \ RRA:MAX:0.5:6:700 \ RRA:MAX:0.5:24:775 \ RRA:MAX:0.5:288:797 Thanks very much for the detailed explanation, Alex! Best wishes Michael -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Alex van den Bogaerdt Sent: 17 August 2001 19:36 To: Michael Wells Cc: RRD users Subject: [rrd-users] Re: Graphs wrong after reboot - samples included Michael Wells wrote: > > I'm finding that when I reboot, the graphs I get are fouled up. An > example of what the graph looks like before and after reboot is here: > > http://www.wells.org.uk/rrdtools/before.png > http://www.wells.org.uk/rrdtools/after.png I need to download these files and rename them to *.gif before I'm able to view them. Did you forget to use '--img-format PNG' ? > rrdtool create rl0.rrd \ > DS:input:COUNTER:3600:U:U \ > DS:output:COUNTER:3600:U:U \ Unlimited counters... so indeed, a reboot results in the counter being reset to zero. If the front end doesn't check the uptime of the counter, it will be processed as a wrap. If the current counter value is below the last-seen counter value then the difference (which is negative) should be incremented with 2**32. If it is below zero thereafter, increment with (2^64 - 2^32) In most cases, 2^32 will have been added. This is 4294967296 bytes which are assumed to have passed the interface somewhere between the previous update and the current one. You write you update every few minutes. However, your RRD is using 300 second intervals. To get the resulting numbers (about 12MBps and about 26MBps) you have to have been updating every three minutes if I'm not mistaking. I also suspect you booted (at least) twice around 18:00 How to solve the problem and the resulting problem: 1) Your front end should check wraps. If it is not a real wrap or if it is not sure to be a wrap, update with "U" instead. 2) If (1) is not possible or not feaseble, set proper limits on the DS. For 10Mbps ethernet this should read "...3600:0:1250000" 3) dump, edit and restore the RRD to get rid of the spike. Search for "2\.6.........e+06" (where \. means a decimal point and . means a character wildcard) in the .xml file. I think there is a script to do (3) but you really want to have a look in such an xml file at least once before automating it. cheers, -- __________________________________________________________________ / [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 -- 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 ********************************************************************** The information contained in this e-mail is confidential and is intended only for the use of the addressee(s). If you receive this e-mail in error, any use, distribution or copying of this e-mail is not permitted. You are requested to forward unwanted e-mail and address any problems to the MIM Holdings Limited Support Centre. e-mail: [EMAIL PROTECTED] phone: Australia 1800500646 International ++61 7 38338042 ********************************************************************** -- 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
