Linux® Quick Fix

You may also want to see graphs of CPU, disk, and memory usage. This chapter explains how to find the values you want to monitor in the SNMP MIB files and then how to use this information to configure MRTG. All the chapter's examples assume that the...

Residing in memory, MIBs are data structures that are constantly updated via the SNMP daemon. The MIB configuration text files are located on your hard disk and loaded into memory each time SNMP restarts. You can easily find your Fedora Linux MIBs b...

Once you identify an interesting MIB value for your Linux system, you can use the snmpwalk command to poll it. Many times the text aliases in an MIB reference the OID branch only and not the data located in a leaf ending in an additional number, such...

Always keep in mind that MRTG refers to MIB counter values as counter values. It refers to MIB integer and gauge values as gauge. By default, MRTG considers all values to be counters. MRTG doesn't plot counter values as a constantly increasing graph...

The UCD-SNMP-MIB MIB keeps track of a number of key performance MIB objects, including the commonly used ones in Table 23.1. Table 23.1. Important Objects in the UCD-SNMP-MIB MIBUCD-SNMP-MIB Object VariableMIB TypeMRTG TypeDescriptionssCpuRawUserCou...

The TCP-MIB MIB keeps track of data connection information and contains the very useful tcpActiveOpens and tcpCurrEstab objects. Table 23.2 details the most important objects in TCP-MIB. Table 23.2. Important Objects in the TCP-MIB MIBTCP-MIB Object...

The MRTG cfgmaker program creates configuration files for network interfaces only, simultaneously tracking two OIDs: the NIC's input and output data statistics. The mrtg program then uses these configuration files to determine the type of data to rec...

cfg # # Configuration file for non bandwidth server statistics # # # Define global options # LoadMIBs: /usr/share/snmp/mibs/UCD-SNMP- MIB.txt,/usr/share/snmp/mibs/TCP-MIB.txt workdir: /var...

Scenario Imagine that your small company has purchased a second-hand Cisco switch to connect its Web site servers to the Internet. The basic MRTG configuration shown in Chapter 22 provides the data bandwidth statistics, but you want to measure the C...

2. Make sure you can do an SNMP walk of the target device. If not, revise your access controls on the target device and any firewall rules that may impede SNMP traffic. 3. Ensure you can do an SNMP get of the specific OID value listed in your MRTG c...

Using the guidelines in this chapter you should be able to graph most SNMP MIB values available on any type of device. MRTG is an excellent, flexible monitoring tool and should be considered as a part of any systems administrator's server management ...