OS Health Monitoring

OS health can be monitored by the N1 System Manager. As part of the add server feature command, with the agentip keyword, you provide credentials to access the monitored server's operating system through ssh with the agentssh keyword. See To Add the OS Monitoring Feature for additional details. This procedure is important for OS health monitoring but not for monitoring hardware health or network reachability.

Adding the OS monitoring feature provides support for OS monitoring and enables monitoring by default. After that, monitoring can be disabled and enabled by use of the set server command. See Enabling and Disabling Monitoring for more information.

Platform OS interface data is obtained through ssh and SNMP. All attribute data is retrieved from the server's operating system by using ssh and SNMP. Statistics related to the central processor unit (CPU) are provided, as is data related to memory, swap usage, and file systems. For the purposes of monitoring, system load data, memory usage, and swap usage data can be categorized as follows:

• System usage, including system idle times

• System load, expressed as the average number of queued processes over 1, 5, and 15 minutes

• Memory usage and memory free statistics, in megabytes and as percentages

• Physical load statistics

• Swap space used and space available, in megabytes and as percentages

• File system used and space available, as percentages

A list of these attributes is provided in Hardware Sensor Attributes.

You can filter OS health monitoring information for all servers by using the show server command:

N1-ok> show server oshealth oshealth

See show server in Sun N1 System Manager 1.2 Command Line Reference Manual for details of possible values of the oshealth filters. For more information and a graphic explaining filtering servers by health state, see To View Failed Servers.

The health of an OS resource can be shown as unknown if the server is reachable but the agent for the monitoring feature cannot be contacted on SNMP port 161. The health of an OS resource can be shown as unreachable if the server is unreachable due to, for example, being in standby mode. See also Understanding the Differences Between Unreachable and Unknown States for Provisionable Servers.

The monitoring of OS health allows you to set specific thresholds for individual monitored servers, or for groups of monitored servers, at the command line by using the set command. See Setting Threshold Values for details.

If you are not interested in the values of some attributes, you can disable the threshold severity for monitoring of those attributes. This action prevents annoyance alarms. Example 5–6 shows you how to accomplish this disabling action.