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Squeezing more Memory Out of a Hyper-V host?

CnicNV
CnicNV asked
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This is a sort of minor nit picky issue I will admit, but I have noticed that there on in the test Hyper-V hosts that I have setup, both of which have 8 GB  of RAM, I can only setup two VMs of 4 GB and 2GB.  In VMware based setups I could get away with 4GB and 3GB, lol I swear I remember even 4 GB and 3.5GB, leaving only 512 MB for the host.  But with Server 2012 Hyper-v it wont let me do this.

When I RDP into the host with the two 4 and 2 GB VMs and fire up task manger, I see that it is only using 6.7 of the 8GB.  I am guessing 6GB for the 2 VMs and 0.7 for the host, how do I gain access to all of the RAM?

Second embedded question, assuming this is a "that's just the way it is" architecture type thing, does this percentage of 16% non usable memory exist even if I had more RAM, like 300 GBs or something very large?

Thanks for the info.
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Network Engineer
Commented:
Hyper-V reserves memory for itself and the host partition. It's a fixed amount, not a percentage of RAM. The relative percent reserved will go down as you add RAM to your hosts.

See http://blogs.technet.com/b/virtualpfe/archive/2011/08/29/hyper-v-dynamic-memory-and-host-memory-reserve-setting.aspx 
and
https://technet.microsoft.com/en-us/magazine/hh709739.aspx

Author

Commented:
Thanks again for the help, this is exactly the information I was after. :-)