Zenoss Thresholds and Hysteresis Possibilities?

Hello,

We have a threshold defined for file systems at 90% utilization. Sometimes a file sytem will hover right around 90%, briefly going over and then dropping back down, clearing the event. I wouldn't really define the behavoir I'm seeing as "flapping" -- it's not happening a few times an hour, but once every couple of days. I found the following solution to this very problem on Zabbix's blog,http://blog.zabbix.com/no-more-flapping-define-triggers-the-smart-way/1488/, and now I'm wondering if Zenoss can do something like this. According to the article, in Zabbix one can define a threshold to define when a problem starts, and then here's the interseting part: it can also define a condition to stay in the problem state. So for instance, if the 90% threshold is breached for a while, but then drops down to 89.9%, one could define a second condition to not clear the event, and instead wait to send the clear until the file system drops down to, for example, 89.0%. This would cut down on the number of excess events that could get generated when something is hovering right around that initial threshold. Anyone know if there is a way to achieve a similar outcome in Zenoss

Thanks!