This is the TriggerQuery from the AlertDefinitions table for your alert. Notice the last bit - "last changed" is only for use with LastBoot.
SELECT DISTINCT Volumes.VolumeID AS NetObjectID,
Volumes.FullName AS Name
WHERE ((Volumes.VolumeType = 'Fixed Disk') AND (100-NullIf(VolumePercentUsed,-2) = 100-NullIf(VolumePercentUsed,-2)
and ((select count(*) from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot') > 0) and NodeID in (select NodeID from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot' and (DateDiff(s, Changed, getdate()) < (60 * 1.2))))) )
So, even though I can set up a conditional with "Has Changed" (Not "Last Changed" as you stated in your post) as an option for "Percent Volume Available" That particular query doesn't actually work?
Is there any way for me to get a trigger to occur when the volume amount changes? Ideally I would like to set it up so that if the volume changes over a 5+ minute time-frame, I get an alert.
The reason I am looking to do this is we had an AS400 server that went from 50% volume utilization to 100% over a 6 hour period filling up with error logs. Yes, having a notification when the HD space is low helps, but having a notification when the volume changes dramatically can also help.
OK, I fixed my problem by creating my own SQL solution.
As was pointed out: Orion Alerts are unable to trigger based "volume -> has changed". I'm no SQL whiz so I am sure you could generate a query from the Volume_Details table, but I went for an easy fix.
In the "Volumes" table, I created 2 new columns: VolumeLastPolledPercent AND VolumeChangeType.
The "VolumeLastPolledPercent" would simply contain a copy of the column "VolumePercentUsed" that I have a script updating every 30 minutes.
The "VolumeChangeType" column has three values: Increase, Decrease or Same. I have a script that runs every 2 minutes to compare the column values in "VolumePercentUsed" and "VolumeLastPolledPercent". I currently have the script only act if the difference is greater than +-2 percent. If it is within the range of -2 to +2, the VolumeChangeType is set to "Same" as in the volumepercent hasn't changed significantly.
But, let's say a large amount of data suddenly gets added to a volume so the percent used goes from 56% up to 60% over a 5 minute period. I now have my alert using a SQL query that checks on the data in "VolumeChangeType". If the change type is set to "Increase" the alert fires and notifies me that the HD space is quickly running out of space.
But, if that amount of data levels off at 60%, the script that copies the values from one column to another runs at the 30 minute interval then the script that compares the differences of the 2 columns runs and resets the "VolumeChangeType" back to same. The trigger is then reset.
The "Decrease" value is for tracking when large amounts of data are deleted. I can be alerted then when that happens.
Again, the reason for all of this is to monitor a server in case the volume suddenly runs out of space (as happened with us). Before the volume is at 100% and crashes the server, we can hopefully fix the problem.
Anyway, I know it's a mouthful but I hope people find it useful. If anyone would like a copy of the SQL queries along with the VB scripts that I run, I'd be happy to post those up.