ORACLE CHM problem handling

Cluster Health Monitor (hereinafter referred to as CHM) is a tool provided by ORACLE that automatically collects the usage of operating system resources (CPU, memory, SWAP, processes, IWeiO, network, etc.). CHM collects data once a second.

These system resource data are very helpful for diagnosing node restart, Hang, instance expulsion (Eviction), performance problems and so on. In addition, users can use CHM to find some problems such as high system load and abnormal memory as early as possible, so as to avoid more serious problems.

In the cluster, you can view the status of the resource (ora.crf) corresponding to CHM with the following command:

Under grid users

$crsctl stat res-t-init

CHM mainly includes two services:

1) .System Monitor

Service (osysmond): this service will run on all nodes, and osysmond will send the resource usage of each node to cluster logger service, which will receive and save all node information to CHM's database.

2) .Cluster Logger Service (ologgerd): in a cluster, ologgerd will have a host point (master) and a standby node (standby). When ologgerd cannot be started on the current node due to a problem, it is enabled on the standby node.

CHM Repository: used to store collected data. By default, it exists under Grid Infrastructure home and requires disk space of 1GB. Each node takes up about 0.5GB space every day. You can use OCLUMON to adjust its storage path and space size.

The following command is used to view its current settings:

$oclumon manage-get reppath

CHM Repository Path = / oracle/app/gridhome/crf/db/bpmjl2

Done

$oclumon manage-get resize

CHM Repository Size = 1094795585