Expensive properties

(imported topic written by TommyG91)

I have created a property called “free space of sys drv”:

((free space of drive of system folder)/(1024 * 1024)) as string & " MB"

I would think that this is an disk IO eater so I have it set to only evaluate once a day.

I want to report on this property and send out a report for all servers with less than 600MB free space. But when I create my auto group, the choices are “contains”, not contains, etc. So a created the group where relevancy = true: free space of drive of system folder / 1000 / 1000 < 600

How often does this hit the client? I don’t want to cause a lot of disk IO on the clients. Also, what if I create a task where the relevancy = true if free space of drive of system folder / 1000 / 1000 < 600? How often will that hit the client?

I’m thinking I should just create another property called “low dsk space” and set the relevancy to show TRUE or FALSE, and then create my group based on that.

(imported comment written by BenKus)

Hey Tommy,

Actually, I believe the file system keeps track of the free space and so you don’t need to do complex calculations to get this info… If you turn on the time reporting in the relevance debugger, you will see it is less than 1ms to get this info:

q: free space of drive of system folder / 1000 / 1000 < 600
A: False
T: 0.589 ms

But if instead you need to iterate through all files to search for something, then that would take a lot of time and IO…

In general, the answer to your question about relevance and Fixlet evaluation is that the agent will keep its CPU/disk usage to be less than 1-2% of resources on the computer and if it finds an expensive property, for most cases it will just go slower when it evaluates it…

Ben

(imported comment written by TommyG91)

Thanks Ben, that clears things up!