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Serg01
Enthusiast
Enthusiast

Reservation CPU

I have a ESXi host 6.5 with 52GHz CPU capacity (2 pSockets * 10 cores * HT = 40 vcpu)

And i want start 2 VMs on host:

VM1 32 vcpu + 35 GHz CPU reservation

VM2 8 vcpu + 15 GHz CPU reservation

but i cant, because get error "The host does not have sufficient CPU resources to satisfy the reservation."

Maximum i can start 35 GHz + 11 GHz  = 46 GHz of 52 GHz.. Why?

How many CPU resources needed by hypervisor?

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4 Replies
Finikiez
Champion
Champion

Why do you want reserve CPU for two VMs on host?

As well HT won't give you twice more performance.

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vijayrana968
Virtuoso
Virtuoso

You can't allocate whole CPU to VMs as there is reservation for ESXI host as well. Please check Hypervisor CPU Overhead

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Serg01
Enthusiast
Enthusiast

Why do you want reserve CPU for two VMs on host?

this is the requirement of the software vendor that works on these VMs

As well HT won't give you twice more performance.

52GHz it "clean" performance, only summation from physical cores

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Serg01
Enthusiast
Enthusiast

You can't allocate whole CPU to VMs as there is reservation for ESXI host as well. Please check Hypervisor CPU Overhead

Thank u for link, but there is only 260 MHz reserved in the System Resource Reservation on host.

52Ghz - 35 - 11 = 6 GHz :smileyalert: reserved by host? 2 core ?? it is sad

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