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rrosenkoetter
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What is DRS based on?

When does ESX decide it's time to move a VM? Based on it's CPU utilization? Memory utilization? %Ready? All of the above?

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bflynn0
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Check out the Understanding DRS section of the Resource Guide[/url] (Page 65).

There are multiple factors DRS uses, but basically it only makes determinations during initial placement (when a VM is powered on) or during resource contention. I don't believe %Ready is used in the calculations, it's pretty much the CPU or Memory load (I don't believe the formulas are published - would like to see them though).

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bflynn0
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Check out the Understanding DRS section of the Resource Guide[/url] (Page 65).

There are multiple factors DRS uses, but basically it only makes determinations during initial placement (when a VM is powered on) or during resource contention. I don't believe %Ready is used in the calculations, it's pretty much the CPU or Memory load (I don't believe the formulas are published - would like to see them though).

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dpomeroy
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Right now CPU and Memory only.

rrosenkoetter
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Am I wrong in thinking that %Ready is a hugely important statistic to monitor? Do the rest of you use esxtop often to check this on fairly loaded host servers?

Multiple times I have experienced host servers running at 60% CPU utilization, VMs showing only 40% CPU utilization in Task Manager, and yet users complain of poor performance on those VMs (which I also experience when I log into the server)

Checking esxtop, I always find %READY to be high (above 15%-20%) for those VMs.. Moving them to a less loaded host server always helps, as %READY drops back below 5%, VM performance gets noticably better...

I find it troubling that DRS doesn't check for this at all...

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Ken_Cline
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%Ready is an important metric, and it would be nice to have DRS keep an eye on it. I think what it boils down to is that DRS (and HA, too) is still an immature technology with lots of room for improvement. I suspect that in future versions you will see not only more data points monitored, but also the ability to have more fine-grained control over how each of those data points is interpreted. (and no. I don't know anything special or secret - just pure speculation!)

So...patience Smiley Happy

Ken Cline VMware vExpert 2009 VMware Communities User Moderator Blogging at: http://KensVirtualReality.wordpress.com/
rrosenkoetter
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So...patience Smiley Happy

You forgot... young grasshopper... Smiley Happy

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Ken_Cline
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So...patience Smiley Happy

You forgot... young grasshopper... Smiley Happy

LOL :smileygrin:

Hey, I saw Grasshopper post the other day - he lives! Mike (a.k.a. grasshopper)...you going to make it to VMworld this year?

Ken Cline VMware vExpert 2009 VMware Communities User Moderator Blogging at: http://KensVirtualReality.wordpress.com/
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