Overcommit Memory?

[AJ1100]

I'm a VMware newby so I apologies for my ignorance.

I have 2 ESX 3.5 servers running VC2.5. I need to migrate 10 VM's from ESX host #2 to host #1. I want to manually VMotion these over. The only resource I'm concerned with is the memory. ESX #1 shows 60% avg max memory used. ESX #2 shows 50%. Can I still migrate these (combine them to #1), without any problems? Do you get errors during migration if memory is past 100%?

Thanks in advance!

AJ

[weinstein5]

Welcome to the forums - you might get some memory contetion but I think it will be tolerable -

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[AndreTheGiant]

I suppose that both hosts have the same RAM.

You are near 100% (probably TSP can reduce the memory usage) so you can migrate the VM without big problems (unless you have high reservation values).

Andre

[aCrazyPenguin]

Hi

As long as you dont have full memory reservations set on each VM you will be okay. However you may experience some performance issues keeping them all on that host if you dont upgrade the memory (might start seeing ballooning). If you do decide to move them over, monitor the memory performance of the VM's to ensure you dont start getting excessive problems.

Regards

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a CraZy PeNguIn

http://www.acrazypenguin.com

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[aCrazyPenguin]

Hi

As long as you dont have full memory reservations set on each VM you will be okay. However you may experience some performance issues keeping them all on that host if you dont upgrade the memory (might start seeing ballooning). If you do decide to move them over, monitor the memory performance of the VM's to ensure you dont start getting excessive problems.

Regards

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a CraZy PeNguIn

http://www.acrazypenguin.com

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[malaysiavm]

In my experience, it should be find as the Hypervisor will take care of the memory overcommit piece. Make sure you dun full reserve all your memory for every single VM.

Craig

vExpert 2009

Malaysia VMware Communities -

[AJ1100]

Some great information. Yes, both hosts have 32GB memory.

[aCrazyPenguin]

Hi

Yes that will be okay. If you had memory reservations in place, you could only move over enough VM's that would "fit" the available memory on the host. But in your case, you can easily over subscribe your memory allocation.

As mentioned before, suggest you monitor your VM performance to ensure you/your users dont get any negative performance effects.

Regards

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a CraZy PeNguIn

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