Linux MIB directory Open and view

In many cases, using MTRG's default configuration to monitor your server's http://www.aliyun.com/zixun/aggregation/10374.html "> network traffic is not enough. You may also want to see CPU, hard disk, and memory usage. This section describes how to find the data you want to monitor in the SNMP MIB and how to use that data to configure MRTG.

The MIB is a data structure that resides in memory and refreshes the data through the SNMP process. The configuration document for the MIB is stored on the hard disk and imported into memory when SNMP is started.

You can find the MIB easily in Fedora Linux by looking for it, and if you add "SNMP" to the instructions, you can filter the output to include data. As you can see in the following example, the MIB is located in/usr/share/snmp/mibs directory:

[Root@bigboy tmp]# Locate MiB | grep snmp/usr/share/doc/net-snmp-5.0.6/readme.mib2c/usr/share/snmp/mibs/usr/share/snmp/mibs/ Disman-schedule-mib.txt ... [Root@bigboy tmp]#

When you edit the MIB settings in the text document, you can find the keyword by using the grep instruction. In the following example, searching for a TCP connection in the MIB, you can see that the search results are RFC1213 and TCP MIB.

[root@silent mibs]# grep-i Tcp/usr/share/snmp/mibs/*.txt | grep 50x15 ... Rfc1213-mib.txt: "The limit on the total number of TCP Connectionsrfc1213-mib.txt:" The number of times TCP 50x15 have Made a ... Tcp-mib.txt: "The number of times TCP 50x15 have made a ... [Root@silent mibs]#

You can also view the MIB through VI deitor. Do not modify them because doing so may cause SNMP to crash. The MIB is very complex, but fortunately those important parts are explained.

One of the data tracked in the MIB is called an object, and each object is pointed to by its object ID or the OID. In this rfc1213-mib.txt file fragment, you can see that the return value when querying the TCP active opens object is the number of Active open TCP connections to the server. The syntax field shows that this is a count value.

MIB typically tracks two types of data. The count value is used to track values that increase over time, such as the number of packets passing through the NIC or the cumulative high load working time of the CPU from the start up. An integer value can be refreshed immediately to track the current amount of memory usage statistics.

Tcpactiveopens object-type SYNTAX Counter ACCESS read-only STATUS Mandatory DESCRIPTION "the number of times TCP 50x15 have made a direct transitions to the syn-sent state from the CLOSED state. ":: = {TCP 5}

Below you can get back to the more different SNMP and MRPG terminology systems. Mastering these differences is important to understanding how to use MRTG to track MIB data.