I find that in many cases when you manipulate volumes they actually change their identifier within SNMP/WMI. As far as Solarwinds sees the volume they were watching before no longer exists and now there is a new volume. It would be nice if Solarwinds automatically added new volumes but they have opted not to go that route so you have to take care of that on your own. What I typically do is set up automatic network discoveries of my server subnets and set them to automatically add in any "new" volumes and then I have powershell scripts that look for scenarios where any node has listings for multiple volumes with the same drive letter where one is up and the other is down and automatically removes the the down copy. Keep in mind that doing something like that will cause you to lose the historical data for the volume.
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