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The following alerts appear on the performance graphs in XenCenter. See the XenCenter online help for more
information:
• vm_cloned
• vm_crashed
• vm_rebooted
• vm_resumed
• vm_shutdown
• vm_started
• vm_suspended
Customizing Alerts
Note:
Triggers for alerts are checked at a minimum interval of five minutes (this avoids placing
excessive load on the system to check for these conditions and reporting of false positives);
setting an alert repeat interval smaller than this will result in the alerts still being generated
at the five minute minimum interval.
The performance monitoring perfmon runs once every 5 minutes and requests updates from XenServer which
are averages over 1 minute, but these defaults can be changed in /etc/sysconfig/perfmon.
Every 5 minutes perfmon reads updates of performance variables exported by the XAPI instance running on
the same host. These variables are separated into one group relating to the host itself, and a group for each VM
running on that host. For each VM and also for the host, perfmon reads in the other-config:perfmon
parameter and uses this string to determine which variables it should monitor, and under which circumstances
to generate a message.
vm:other-config:perfmon and host:other-config:perfmon values consist of an XML string like
the one below:
<config>
<variable>
<name value="cpu_usage"/>
<alarm_trigger_level value="LEVEL"/>
</variable>
<variable>
<name value="network_usage"/>
<alarm_trigger_level value="LEVEL"/>
</variable>
</config>

Valid VM Elements

name
what to call the variable (no default). If the name value is one of cpu_usage, network_usage, or
disk_usage the rrd_regex and alarm_trigger_sense parameters are not required as defaults
for these values will be used.
alarm_priority
the priority of the messages generated (default 5)
alarm_trigger_level
level of value that triggers an alarm (no default)
alarm_trigger_sense
high if alarm_trigger_level is a maximum value otherwise low if the alarm_trigger_level
is a minimum value. (default high)