When you set alert actions for an event, you can specify the action
to display an alert on the server. To perform this action, Server
Administrator sends a message to
/dev/console. If the Server Administrator system is running an X Window System,
the messsage is not displayed. To see the alert message on a Red Hat
Enterprise Linux system when the X Window System is running, you must
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, you must start a terminal such
as
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 Server
Administrator system is running an X Window System, the message is
not displayed by default. To see the broadcast message when the X
Window System is running, you must 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 application. There are limitations on the applications
that Server Administrator can execute. 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
stdout and
stderr 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 insert the full path to the
script in the
Absolute path to the application box.
Example 1:
ps -ef >/tmp/psout.txt 2>&1
The command
in Example 1 executes the application ps, redirects stdout to the
file
/tmp/psout.txt, and redirects
stderr to the same
file as
stdout.
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.txtto the Red Hat Enterprise Linux user or SUSE Linux Enterprise Server
user, and Administrator, with the subject
Server Alert. The
file
/tmp/alertmsg.txt must be created by the
user before the event occurs. In addition,
stdout and
stderr are redirected to the file
/tmp/mailout.txt in case an error occurs.