ESXi 6 and VM with 2TB of Memory

Earlier today I fat figer a setting on a VM and instead of giving it 2GB I gave it 2GB. Now mind you the host only has 196GB of ram. I was a bit surprise the configuration even complete without error. I figure out the error after I powered up the VM and saw the error.

How could Vmware let this config succeed even though the host only had 196GB of ram. Yes I know you can over commit a host thanks to different memory saving techniques but this seem excessive. How was I even able to power up the VM? Maybe the host force other Vm to balloon?
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compdigit44Asked:
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Andrew Hancock (VMware vExpert / EE MVE^2)Connect With a Mentor VMware and Virtualization ConsultantCommented:
It's called Over Commit!

VM and Host have swap files, and you and you can use Flash/SSD rather than slow spinning rust.

Never used Swap to Cache ? SSD ? or PCI-E flash cards ?

http://www.yellow-bricks.com/2011/08/18/swap-to-host-cache-aka-swap-to-ssd/

I'm surprised you've never done it as a test to see what happens, and set to 4TB! and what the host go slow, and stop responding...and swap like made, and hit the disk I/O, and CPU goes 100%

It's not really VMware fault...

Give a child a Loaded Gun, and he'll shot himself by accident!
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Richardson PortoSenior Infrastructure SpecialistCommented:
After exhaust all the physical memory (and use TPS, memory compression and balloon), VMware will use virtual swap through the file .vswp located by default on the same folder of your virtual machine, but of course with will be slower than real memory.
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compdigit44Author Commented:
Thanks everyone...

After I powered up the VM the page file within the guest quickly expand filling up the drive. Granted this was on a test host that host our Dev VM but they connected to run and the host did not throw any alerts about high memory usage...
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