Memory Tax

[vmNewb35]

A buddy of mine said that when he sat his VCP he got some question about "memory tax"??? What exactly is this and where can I read about it? I don't want any surprises when I finally get ready to take this (which is still a ways off). I searched the forums and didn't find anything about it.

Any thoughts? Thanks, Chad

[rsa911]

your friend was maybe talking about memory ballooning ?

[esiebert7625 · Accepted solution]

These docs cover it pretty well...

Memory Resource Management in VMWare ESX Server - http://www.stanford.edu/~stinson/cs240/cs240_1/revs/esx.txt

The Role of Memory in ESX Server 3 - http://www.vmware.com/pdf/esx3_memory.pdf

Memory resource management in Vmware ESX Server - http://www.vmware.com/pdf/usenix_resource_mgmt.pdf

If a virtual machine is not actively using its currently allocated memory, ESX Server charges a memory tax — more for idle memory than for memory that is in use. That is, the idle memory counts more towards the share allocation than memory in use. The default tax rate is 75 percent, that is, an idle page of memory costs as much as four active pages. This rate can be changed by modifying a parameter setting.

Memory tax helps prevent virtual machines from hoarding idle memory. The approach in ESX Server ensures that a virtual machine from which idle memory has been reclaimed can ramp up quickly to its full share-based allocation once it starts using its memory more actively.

Fyi…if you find this post helpful, please award points using the Helpful/Correct buttons.

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Thanks, Eric

Visit my website: http://vmware-land.com

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[vmNewb35]

Thanks Eric -- I figured you would have heard of this...perhaps you need your own messaged boards for "Ask Eric"!

[rsa911]

Thanks for the links & explanation Eric, time for me to re-read them !

you definitively rule

[admin]

Eric needs to slow down a little...another 6000 points...and he'll be a guru. With nothing more to conquer...no more levels to reach on the board, I've heard that some guys go crazy...never to be heard from again.

This is a great board...and would be nothing without the people who ask and answer questions. I've never experienced another forum where people have to "race" to answer the questions of others. It's a big family here.

Chris

[esiebert7625]

Ha! I think KevinG will be defining the next level soon, he's well on his way to the 50K mark.

Yeah you have to be quick here, not a bad problem to have. Multiple replies from different people are always good since they offer various viewpoints and solutions to problems.

[admin]

Yeah, KevinG has got to be a one man VMware support department. Maybe he gets paid per correct answer.

Chris

[vmNewb35]

You're exactly right Chris -- I have never seen a more professional and successful board. Things are answered here so quickly it's like having a virtual genius in your datacenter. It's nice when technology is dealt with like this...makes things go so much smoother and makes you appreciate your job.

I finally answered a couple of questions last week correctly and I actually was glowing...what's up with that???

[admin]

Chad,

I see you're moving up in the points quickly as well. It won't be long before you reach Expert status at 1000. It's taken me forever to get past 1000....and I'm closing in on 2000. Looking for my crown before the end of the year.

You're right, it does make you feel good contributing to something big...and helping others. If other virtualization platforms out there have any hopes of catching VMware...they better start thinking about developing a great forum as well in addition to pricing and product features.

These forums are a major reason why VMware has gained so much popularity...especially from the mainstream crowd, in my humble opinion. Yes, we all know that they have great products, but without great support, it doesn't really matter.

To tell you how great these forums are...just look at all of the non-VMware related questions posted out here. You can probably ask just about any technical question relating to any hardware or software vendor...and someone will have an answer for you. These forums are bigger than VMware. I can only hope that they keep this good thing going at least until I can retire.

Chris

[esiebert7625]

Well put. I like helping others and sharing my knowledge and experiences in these forums. Also helping and teaching others is a great way to help yourself learn more and grow.

[vmNewb35]

You are spot on with this statement:

>>Yes, we all know that they have great products, but without great support, it doesn't really matter.

These boards are better than ANY support/maintenance plan I have ever witnessed.

[FredPeterson]

You are spot on with this statement:

>>Yes, we all know that they have great products, but

without great support, it doesn't really matter.

These boards are better than ANY support/maintenance

plan I have ever witnessed.

Nothing beats real world experience except easy access to people who have already had their own real world experiences and are willing to share it.

[vmNewb35]

You ain't kiddin' there Fred!