Linux server set up: My CACTI--FAQ

Linux Server Setup: My CACTI--FAQ-Linux Enterprise Application-Linux server application information, the following is read details. 1. Global:

1. What is CACTI? What is its use?

2. Where is the official cacti website?

3. Where can I download it?

4. How can I install it?

5. What does cacti need?

6. Why can't I find the snmpwalk and snmpget commands?


Ii. Usage:

1. Why can't images be displayed?

2. Why is there nothing in the rra directory?

3. Why can I retrieve traffic data but cannot retrieve CPU and memory data?

4. Can I retrieve data from a local machine (linux), but cannot retrieve data from a remote host?

5. I used MRTG for traffic monitoring. Can I import data from MRTG to Cacti?

6. Why am I not sure if my traffic reaches MB?

7. 02:59:58-POLLER: Poller [0] Maximum runtime of 296 seconds exceeded. Exiting?

8. How can I back up Cacti and its data?

9. How to merge data? How to customize scripts?

10. Use the monitor and threshld plug-ins

11. Why are the characters in the monthly or yearly traffic diagram garbled?

12. Does cacti support Chinese?

13. Is the status in the Data Query of the newly created device always "Success [0 Items, 0 Rows]"?




1. Global:


1. What is CACTI? What is its use?

Cacti is a PHP program that uses snmpget to collect data and rrdtool to plot data. Cacti can be used to count network devices


You can also customize monitoring metrics for traffic, CPU, system load, and other parameters.


2. Where is the official cacti website?

Http://www.cacti.net


3. Where can I download it?

Http://www.cacti.net/download_cacti.php


4. How can I install it?

Official installation documents: http://www.cacti.net/documentation.php

I wrote installation documentation: http://bbs.chinaunix.net/viewthread.php? Tid = 594019


5. What does cacti need?

Must have certain knowledge of using net-snmp and rrdtool.

If you want to customize monitoring metrics, you also need some shell script or xml language capabilities. If you want to help cacti development


You need to be familiar with php scripts.


6. Why can't I find the snmpwalk and snmpget commands?

Install a new net-snmp package or create a net-snmp-utils package.


Ii. Usage:


1. Why can't images be displayed?

Make sure that the configuration of your IP address, snmp comunite, snmp version, and other information is correct.


To install cacti in linux, follow these steps:

1.1. Both data sources and Graph Management of cacti have debug. Check whether an error exists. For example, the rrd file cannot be found.


1.2. Check the rrd file name in data sources and check whether the file exists in the/cacti/rra directory.


1.3 if an rrd file exists, you can use



CODE: [Copy to clipboard] rrdtool fetch yourRRDfile. rrd AVERAGE

Command to view the collected data of the file. If they are all "nan", no data is obtained.


1.4. The paths of snmpget, snmpwalk, and rrdtool may be incorrect.


1.5 after troubleshooting, you need to re-establish the Monitoring point (graph ).


Tip: each image file is saved as a file with the suffix rrd In the rra directory (you can see it in "Data Sources)


. Debug can be performed on both "Data Sources" and "Graph Management", and error messages can be obtained from debug.



2. Why is there nothing in the rra directory?

2.1. view the permission for this directory. The permission for this directory should be cactiuser and can be read and written.


2.2 If the directory permission is correct, it may be due to an error in snmp settings. Please test it manually:



CODE: [Copy to clipboard] snmpwalk-v 2c-c public yourIP if

If any data is returned, the snmp data is correct. If a message such as "Timeout: No Response from..." appears


The error message is a problem with snmp settings.


2.3. The Paths of snmpwalk, snmpget, and rrdtool may not be set properly in Settings-> Paths to check whether the Settings are correct.


Please re-build the monitoring site after modification! Otherwise, it does not take effect.



3. Why can I retrieve traffic data but cannot retrieve CPU and memory data?

It should be the problem of setting snmp permissions. You can manually test it using snmpwalk.

To retrieve CPU and other data, you need to modify the net-snmp configuration. For details about how to modify the settings, see:

Http://bbs.chinaunix.net/viewthread.php? Tid = fourth floor of 594019.



4. Can I retrieve data from a local machine (linux), but cannot retrieve data from a remote host?

Cacti has many templates, some of which use SNMP for data collection, and some use shell scripts for data collection. We recommend that you use SNMP for no special reason.

Associated Graph Templates

The previous template with "ucd/net" is the template that can use ucd-snmp and net-snmp. For example, ucd/net-CPU Usage

Associated Data Queries

SNMP can be used. For example, SNMP-Interface Statistics


Of course, you can also find new templates or add your own templates from www.cacti.net.



5. I used MRTG for traffic monitoring. Can I import data from MRTG to Cacti?

Of course! Because that's what I do.

Please see: http://bbs.chinaunix.net/viewthread.php? Tid = 595090



6. Why am I not sure if my traffic reaches MB?

This is related to the snmp version. The data in snmp1 is 32-bit while that in snmp2c is 64-bit.

First, make sure that you are using snmp2c or above (currently supported by network devices ).

Click "Console->; Create New Graphs->; Data Query" on the Cacti page ". You can see below

Select a graph type: "drop-down menu (In/Out bits by default). To retrieve 64 bits data, change it

"In/Out bits (64-bit Counters)", and then select the network card you want to monitor.

In addition, the "Maximum Value" of the monitoring site must be set to more than MB.


If a Linux host needs to monitor traffic of more than MB (usually not occurring), it needs to re-compile the latest net-snmp with the "-- enable-mfd-rewrites" parameter.



7. 02:59:58-POLLER: Poller [0] Maximum runtime of 296 seconds exceeded. Exiting?

It should be because you have too many monitoring points, so that cacti has obtained all data through snmpget for more than 300 seconds.

The author of Cacti considered this problem early in the morning, so there are two solutions in cacti:


7.1 change POLLER to cactid.

The default POLLER is cmd. php, and cactid is a program written in C, which is several times more efficient than cmd. php!

Note that cactid is not installed by default even if you select it.

You can download the source code or rpm (bin) file of cactid from here (http://www.cacti.net/cactid_download.php) for installation. Then, specify the cactid PATH in the PATH.


7.2 increase the number of cmd. php processes in POLLER settings, that is, run multiple cmd. php programs to collect data at the same time. However, this will increase your system load.

If your machine has poor performance, it is recommended to use cactid instead.


PS: this problem occurs when the disk space is full because the slow disk space leads to a longer snmpget time.


8. How can I back up Cacti and its data?

You only need to back up the rra directory and database. You can also back up the log directory together.

If you have added some plug-ins, copy them.


9. How to merge data? How to customize scripts?

Please see: http://bbs.chinaunix.net/viewthread.php? Tid = 631801


10. Use the monitor and threshld plug-ins

Please see: http://bbs.chinaunix.net/viewthread.php? Tid = 631801

The fourth floor.


11. Why are the characters in the monthly or yearly traffic diagram garbled?

Answer:


This is because rrdtool does not support Chinese characters. My situation is even more serious. When Chinese characters appear in the figure, the segment fault is lost during rrdtool graph.


Because the date display in the Chinese environment displays the week and month as Chinese by default, garbled characters appear in your graph because Chinese characters cannot be displayed.


There are two ways to solve this problem. One is to enable rrdtool to display the English date, and the other is to enable rrdtool to support Chinese characters. Both methods involve modifying the source code of rrdtool. I am taking the first idea, so that rrdtool should not read the language environment variables in the Chinese environment and force it to use English.


When compiling rrdtool1.2, I changed the content in the src/rrd_graph.c file:


Setlocale (LC_TIME ,"");

Change

Setlocale (LC_ALL, "en_US.ISO-8859-1 ");


Then compile. That's all. If not, change the language environment in your environment variables to English:

Export LC_ALL = en_US

Export LANG = en_US

Export LANGUAGE = en_US

Export LC_CTYPE = en_US

Export LC_TIME = en_US


Or, you just need to let rrdtool support Chinese Based on abel's approach.

Http://bbs.chinaunix.net/viewthr... p; extra = & page = 1


12. Does cacti support Chinese?

By default, cacti cannot display Chinese characters on some pages, and rrdtool cannot display Chinese characters by default.

If you really need to use Chinese characters, refer to the following link.

Http://bbs.chinaunix.net/viewthread.php? Tid = 631801


13. Is the status in the Data Query of the newly created device always "Success [0 Items, 0 Rows]"?


Check whether the permission settings in your snmpd. conf allow cacti to retrieve the data of these OID. You can use the snmpwalk command for testing, for example:


CODE: [Copy to clipboard] snmpwalk-c community-v 2c hostIP if

If your snmpd. conf settings are correct, it may be the following:

Earlier versions of snmpwalk (such as redhat 5.0.6 installed by default) lack some parameters, such as the "U" parameter in-O (you can use snmpwalk -- help to check whether this parameter exists ).

While cacti-0.86g or later versions require these parameters, the solution is to install a new net-snmp package (such as: net-snmp5.2.1) to get a new snmpwalk version.


For more information, see

Www.cacti.net

Check it out. There is an official forum where you can ask questions.