Vmware CPU Issues

ChRoNo16

[H]ard|Gawd
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Feb 3, 2011
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Im running a supermicro server, its got dual E5-2650's 8c/16t

This is the version im running
6.5.0 Update 3 (Build 17477841)

The issue im having is I cannot add more than 1 cpu per VM.
it allows me to add 1cpu socket
the selector for core count is greyed out at 1

I cannot figure out how to fix it. Checked settings in bios and hyperthreading and virtualization are enabled.

How do I fix this?
 

gimp

[H]F Junkie
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Jul 25, 2008
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you changed CPU to 2 first, and Cores per Socket is still greyed out?
VM powered off if Enable CPU Hot Add is not enabled?
 

ChRoNo16

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yes powered off, no cpu hot add enabled, 1 chaged cpu sockets to 2, which allowed for two cored, but I want to be able to run 1 socket 4 cores.
 

gimp

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yes powered off, no cpu hot add enabled, 1 chaged cpu sockets to 2, which allowed for two cored, but I want to be able to run 1 socket 4 cores.
CPU needs to be set to the total number of cores you want, regardless of vCore or vCPU count. Then you adjust Cores per Socket to get what you want.

In your case you need to set CPU to 4, then you should be able to set Cores per Socket to 4.

1639939945605.png


If I wanted total of 4 vCPU but 2 sockets, I just change Cores per Socket to 2.

1639940012671.png


Unless I'm just misunderstanding.

There was a bug in an older build of ESXi 6.5 that prevented doing more than 2 Cores per Socket, but that was a build prior to Update 1.
https://kb.vmware.com/s/article/53354
 

gimp

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But why cant it be 1 cpu socket, with 4 cores?
wat
it can, as shown in the first screenshot I posted.
4 CPU with 4 cores per socket, so Sockets = 1

screenshot from the ESXi host web console
1639944106283.png


CPU = total core count, regardless of cores per socket or number of sockets.
you then expand CPU configuration to configure Cores per Socket. Set Cores per Socket to same number as CPU to get Sockets: 1
 
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ChRoNo16

[H]ard|Gawd
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I dont know what I was doing wrong, but now it isnt greyed out. works fine like youve shown. I just dont get it, but it works now so im happy. thank you for the help
 

bigdogchris

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Feb 19, 2008
Messages
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But why cant it be 1 cpu socket, with 4 cores?
VMware used to recommend you assign sockets rather than cores (so yes, like 8 sockets 1v core each on an 8 core system) but they have lightened up on this over time. It is the default though even to this day, and they recommend only assigning cores per socket if you have a socket licensed software on the machine.
 
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