volume space monitoring and alerting question

dmcconnell

Hi,

I want to be able to set a specific size or "alert threshold" for volumes within NPM.  I created a custom property in volumes called "AlertThreshold."  I can enter the number of bytes into this custom property and create an advanced alert that triggers when the volume is below this threshold.  It all works flawlessly.  So the way that I would like it to work, is instead of entering the threshold in bytes, i could enter it into megabytes.  I'm not finding a way to use advanced alerts with the value in megabytes though.  So what I'm thinking of doing is create another custom property called "AlertThresholdMB", then creating an update trigger in the database that would populate the AlertThreshold property with (AlertThresholdMB * 1024 * 1024) and leaving the alert the way it is.  Does anyone have a better way of doing this?

Thanks
David

smargh

I wanted to do the same. You can't put anything larger than 2147483648 bytes (2GB) into a custom property of type "integer", which is what it needs to be for the comparison to be successful.

You can manually insert the trigger & reset SQL into the AlertDefinitions table. However, you must never edit *anything* in the GUI for the alert, otherwise the GUI trigger & reset definitions are re-evaluated and the custom SQL is overwritten.

I use these queries. They can probably be optimised, but they work for me. Let me say again: you must remember to never edit *anything* in the GUI for this alert. Perhaps you could set a trigger on UPDATEs to the table to automatically re-insert the TriggerQuery and ResetQuery SQL.

Perhaps another option would be to very regularly run an MSSQL Agent job (or a trigger) to calculate the free megabytes & write it to a custom property. Then, you could just set up a regular alert and compare the custom properties. That might actually be better than my current method.

Custom SQL in trigger definitions is on the APM todo list, and will hopefully be added soon. It is quite low on the list though

 

-- TriggerQuery
SELECT Volumes.VolumeID AS NetObjectID, Volumes.FullName AS Name FROM Nodes INNER JOIN Volumes ON (Nodes.NodeID = Volumes.NodeID) WHERE ( (Volumes.Minimum_Free_MB IS NOT NULL) AND (Nodes.Vendor = 'Windows') AND ((Volumes.VolumeType = 'Fixed Disk') OR (Volumes.VolumeType = 'Unknown')) AND VolumeSpaceAvailable <> -2 AND (((NullIf(VolumeSize,-2)-NullIf(VolumeSpaceUsed,-2))/1024)/1024 < Minimum_Free_MB) AND (Volumes.VolumeSize > 1))

-- ResetQuery
SELECT Volumes.VolumeID AS NetObjectID, Volumes.FullName AS Name FROM Nodes INNER JOIN Volumes ON (Nodes.NodeID = Volumes.NodeID) WHERE NOT ( (Volumes.Minimum_Free_MB IS NOT NULL) AND (Nodes.Vendor = 'Windows') AND ((Volumes.VolumeType = 'Fixed Disk') OR (Volumes.VolumeType = 'Unknown')) AND VolumeSpaceAvailable <> -2 AND (((NullIf(VolumeSize,-2)-NullIf(VolumeSpaceUsed,-2))/1024)/1024 < Minimum_Free_MB) AND (Volumes.VolumeSize > 1))