Alert for Logical disk space capacity available for Hosts .

Ok, this is a good thing to do, since % isn't always the most important thing to monitor for.  e.g. you always need 50GB free disk space on a datastore, regardless of % in use.

**** ALWAYS COPY A RULE, AND THEN MODIFY IT  ***

First, you have to determine what you are going to compare, and what threshold you want to compare it to.  Sadly, this particular rule isn't written very clearly as an example.

The current rule uses a scope of VMWVirtualMachineLogicalDisk:

The fatal rule condition is currently:

try{

vmStateObjs = #vmState from $scope.virtualMachine#;

tmpList0 = vmStateObjs?.values(vmStateObjs?.topologyObjects[0]);

if(tmpList0==null || tmpList0.size() == 0) {

return false;

}

vmState= tmpList0.get(0)?.getValue();

qObjs = #capacityAvailable from $scope.hostLogicalDisk#;

tmpList = qObjs?.values(qObjs?.topologyObjects[0]);

if(tmpList==null || tmpList.size() == 0) {

return false;

}

availbility = tmpList.get(0)?.getValue()?.getAvg();

if((vmState==null) || (availbility == null) || (!vmState?.equalsIgnoreCase("poweredOn"))) 

    return false;

@rulette_data["VmState"] = vmState;

@rulette_data["Availbility"] = availbility ;

if(availbility<=registry("VMW:vmLogicalDrive.fatal")) return true;

else return false;

} catch (Exception e) {return false;}

availbility is stored as 0-100 (%) of the total disk space on the logical drive.

In order to create a rule which compares to actual disk free, we need a different query

to retrieve 'spaceAvailable', which is stored in megabytes.

So, for our new rule, we will need:

qObjs = #spaceAvailable from $scope.hostLogicalDisk#;

        tmpList = qObjs?.values(qObjs?.topologyObjects[0]);

    if(tmpList==null || tmpList.size() == 0) {

    return false;

    }

    spaceAvailable = tmpList.get(0)?.getValue()?.getAvg();

return spaceAvailable;

Now, we can change the comparisons in the Critical and Fatal to alert

on the comparison of spaceAvailable to a new registry variable called

Host.LogicalDiskCapacityAvailable.fatal which is set to a value of 10240, 

and Host.LogicalDiskCapacityAvailable.critical which could be set to something like 20480.

Both are in megabytes to match the scale of spaceAvailable.

The new fatal rule would then be something like:

try{

vmStateObjs = #vmState from $scope.virtualMachine#;

tmpList0 = vmStateObjs?.values(vmStateObjs?.topologyObjects[0]);

if(tmpList0==null || tmpList0.size() == 0) {

return false;

}

vmState= tmpList0.get(0)?.getValue();

qObjs = #spaceAvailable from $scope.hostLogicalDisk#;

        tmpList = qObjs?.values(qObjs?.topologyObjects[0]);

    if(tmpList==null || tmpList.size() == 0) {

    return false;

    }

    spaceAvailable = tmpList.get(0)?.getValue()?.getAvg();

if((vmState==null) || (spaceAvailable == null) || (!vmState?.equalsIgnoreCase("poweredOn"))) 

    return false;

@rulette_data["VmState"] = vmState;

@rulette_data["spaceAvailable"] = spaceAvailable ;

if(spaceAvailable<=registry("Host.LogicalDiskCapacityAvailable.fatal")) return true;

else return false;

} catch (Exception e) {return false;}

Notice that the @rulette_data values are set in the Fatal level,

and then can be used in the Critical level without re-calculating them.

The Critical condition would then become:

try{

vmState = @rulette_data["VmState"];

spaceAvailable = @rulette_data["spaceAvailable"];

if((vmState==null) || (spaceAvailable==null) || (!vmState?.equalsIgnoreCase("poweredOn")))  return false;

if(spaceAvailable<=registry("Host.LogicalDiskCapacityAvailable.critical")) return true;

else return false;

} catch (Exception e) {return false;}

You will also want to look at the Behaviour tab, as you want to prevent 'thrashing'

if space available goes over and under a threshold on a regular basis. 

You might want your rule to be set to something like Fire after 2 consecutive failures, waiting 30 min between.