Nisha, For reference, this is the script I use in order to tune my files (I graph cable modem signal levels and I have to tune all the files to allow them to display negative dB values)
for RRD in `ls /var/www/mrtg/*/*-down.rrd` ; do rrdtool tune $RRD -i ds0:-60 -a ds0:60 blah ; done You will obviously have to modify the values to match your setup.. HTH -- Simon Westlake -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of S Shipway Sent: Wednesday, October 21, 2009 5:29 PM To: [email protected] Subject: Re: [mrtg-developers] Mathematical operations on OIDs MRTG is able to handle negative values, provided that: a) you are using RRDTool as your backend, not native mode, and b) You manually set the Minimum for the DS appropriately within the RRD file using RRDTune (MRTG always sets the minimum to 0). Also, unless this is a gauge, you might need to use 'derive' rather than 'counter' in order to cope with negative slopes. Steve ________________________________ From: nisha [via MRTG Mailinglists] [mailto:[email protected]] Sent: Wednesday, 21 October 2009 11:04 p.m. To: Steve Shipway Subject: RE: [mrtg-developers] Mathematical operations on OIDs Hi Steve, This solution worked. But now i have a problem when the calcualtion results in a negative value. Lets say [oid1 - (oid2 * 5)] gives a positive value and [oid3 - (oid4 * 10)] gives a negative value then the rrds are not able to update these values and hence my graph shows Nan Have you come across something like this before? Can mrtg can handle this? Regards, Nisha S Shipway wrote: This is not possible as you state it; Target line calculations can only be done on an OID pair. However you might achieve it like this: Target[targetname]: oid1&oid3:co...@host - ( oid2&oid4:c...@host * 5 + ( pseudoZero&oid4:co...@host * 5 ) ) Note that the spaces around the brackets and arithmetic signs are essential. 'pseudoZero' is a magic MRTG virtualOID that always resolves to zero. Check the documentation on complex calculated Target lines online at www.mrtg.org<http://www.mrtg.org/> or get a copy of the book from www.steveshipway.org/book<http://www.steveshipway.org/book> Your example below is using oid4x10 in one place but oid4x8 in another but I guess that's just a typo. Steve ________________________________ From: nisha (via Nabble) [mailto:[email protected]] Sent: Thursday, 27 August 2009 11:02 p.m. To: Steve Shipway Subject: [mrtg-developers] Mathematical operations on OIDs Hi all, I want to perform mathematical operations on OIDs in the target line. For example, there are 4 oids as shown below: traffic packet In oid1 oid2 Out oid3 oid4 Now i want to apply the following formula traffic in = oid1 - (oid2 * 5) traffic out = oid3 - (oid4 * 10) My target line in router cfg file is like this: Target[targetname]: oid1&oid3:c...@hostname - (oid2 * 5)&(oid4 * 8):c...@hostname Is this possible in MRTG? Can the router cfg file handle oids with mathematical operations? ________________________________ View message @ http://n2.nabble.com/Mathematical-operations-on-OIDs-tp3524231p3864251.html To start a new topic under MRTG Developers Mailinglist, email [email protected] To unsubscribe from MRTG Developers Mailinglist, click here< (link removed) =>. -- View this message in context: http://n2.nabble.com/Mathematical-operations-on-OIDs-tp3524231p3868979.html Sent from the MRTG Developers Mailinglist mailing list archive at Nabble.com. _______________________________________________ mrtg-developers mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/mrtg-developers This E-mail and any of its attachments may contain Time Warner Cable proprietary information, which is privileged, confidential, or subject to copyright belonging to Time Warner Cable. This E-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this E-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this E-mail is strictly prohibited and may be unlawful. If you have received this E-mail in error, please notify the sender immediately and permanently delete the original and any copy of this E-mail and any printout. _______________________________________________ mrtg-developers mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/mrtg-developers
