Setting Alert Actions
Setting Alert Actions In Linux Operating Systems
When you set Alert Actions for an event on systems running a supported Linux operating system, you can specify the action to "display an alert on the server." To perform this action, Server Administrator writes a message to the console. If the Server Administrator system is running an X Window System, you do not see the message by default. To see the alert message on a Red Hat Enterprise Linux system when the X Window System is running, start xconsole or xterm -C before the event occurs. To see the alert message on a SUSE Linux Enterprise Server system when the X Window System is running, start xterm -C before the event occurs.
When you set Alert Actions for an event, you can specify the action to 'broadcast a message'. To perform this action, Server Administrator executes the wall command, which sends the message to everybody logged in with their message permission set to yes. If the system running Server Administrator is running the X Window System, you do not see the message by default. To see the broadcast message when the X Window System is running, start a terminal such as xterm or gnome-terminal before the event occurs.
When you set Alert Actions for an event, you can specify the action to 'execute an application'. Limitations are on the applications that Server Administrator can execute. Follow these guidelines to ensure proper execution:
- Do not specify X Window System-based applications because Server Administrator cannot execute such applications properly.
- Do not specify applications that require input from the user because Server Administrator cannot execute such applications properly.
- Redirect the stdout and stderr commands to a file when specifying the application so that you can see any output or error messages.
- If you want to execute multiple applications (or commands) for an alert, create a script to do that and put the full path to the script in the application to execute box.
Example 1: ps -ef >/tmp/psout.txt
2>&1
The command in Example 1 executes the application ps command, redirects the stdout command to the file /tmp/psout.txt, and redirects the stderr command to the same file as the stdout command.
Example 2: mail -s "Server Alert" admin </tmp/alertmsg.txt>/tmp/mailout.txt
2>&1
The command in Example 2 executes the mail application to send the message contained in the file /tmp/alertmsg.txt to the Linux user, the Admin, with the subject "Server Alert." The file /tmp/alertmsg.txt must be created by the user before the event occurs. In addition, the stdout and stderr commands are redirected to the file /tmp/mailout.txt if an error occurs.