Resource utilisation on esx server

[mjohn3]

I have esx with 4 dula-core AMP processors with 2.8 GHz. It is hp proliant hardware. I have installed 6 guest systems on it and facing cpu/memory utilisation problem.

How to improve it and so I can add more guest OS on same host? I can not add more resources now. Provide me any help for this.

[weinstein5]

Need a little more information - How much memory does your ESX host have? How many virtual cpus ahve your assign to each of your virtual machines? How much memory have you assigned to your virtual machines? Are you using resource pools? How did you determine that that your are facing memory/cpu utilization probelms?

[mjohn3]

Host config:

4 CPU X 2.8GHz

16GB RAM

2 CPU per guest/ virtual machine

2GB memory per guest

I am not aware of resource pool. New to vmware.

I am checking CPU graphs on host and guest. Also due to maximum utilization, it shows yellow clored warning like Memory usage in Alarms.

[weinstein5]

The first thing I would do is drop your VMs back to a single vCPU - because what you may be experiencing is scheduling problems with the vcpus - best practice is start with a single vcpu and add another only if you need to -

[mjohn3]

So, you mean that every VM should be created with only one vCPU and then increased by the time.

So, if I have created Vm with 2 vCPU and some with 1 vCPU then it will create this kind problem, is that you mean or not?

[weinstein5]

the issue is the vmkernel schedules both vCPUs simultaneaously so if it does not have the capacity to schedule both it will schedule neither and the vm will stop processing until it can schedule both- think of it this way it is easier to schedule a single cpu than two or four -

[mjohn3]

this is present situation..what to do? what is the solution?

[kumarkv]

Hey

Drop all VM to 1 vCPU. When you make that chnage you need to have the CPU drive in the OS chnaged to ACPI uniprocessor.

For Each VM ...What is the assigned memory...Check the memory utilization and tell me how much each VM consumes.

For Critical VM set a Reservation and a limit This would ensure that their is no over allocation.

Regards

Kumar

[kumarkv]

Hey

Drop all VM to 1 vCPU. When you make that chnage you need to have the CPU drive in the OS chnaged to ACPI uniprocessor.

For Each VM ...What is the assigned memory...Check the memory utilization and tell me how much each VM consumes.

For Critical VM set a Reservation and a limit This would ensure that their is no over allocation.

Regards

Kumar

[mjohn3]

hey,

that i can't bcz all are in use. can you tell me or refer me some link so i can see how should be the actual cpu to vcpu ration in esx server for good performance?

[kumarkv]

Hey

1. How many CPU's are assigned to each VM (1 CPU is very ideal)

2. How much memory has been allocated for each VM?

3. Are your existing servers too busy...check the performance graphs for memory ballooning?

4. Enable Performance counter in one of your VM's and check which is the bottleneck

5. Are all these VM's residing on the same storage /LUN? Its better to seggregate depending on disk I/O

6. Create a resource pool and set reservation and limit for each VM

This should improve performance and allow you to add more VM's . Go through the resource management guide and you will get more info.

[mjohn3]

I have given info for rest.

Now, how to do this: Enable Performance counter in one of your VM's and check which is the bottleneck

I have shared LUNs to VMs but not only one LUN. I have 4 LUNs.

Create a resource pool and set reservation and limit for each VM

--- how to create this.

Is there any limit to assign CPU to VMs. I need to add CPU to two VMs because they are showing yellow alarm every 10 min.

[Ken_Cline]

Moved to the Performance forum.

As others have said, best practice is to create your VMs with a single vCPU and scale up to vSMP configurations as the load warrants.

Some good places to start reading:

- Single vs Multi Processor VM's

- Performance SR Checklist

- Documents in the Performance Forum

Based on what you've specified:

- 4 (dual core) CPU X 2.8GHz

- 16GB RAM

- 2 CPU per guest/ virtual machine

- 2GB memory per guest

You should not be seeing memory contention. If you have only six VMs running, you have enough physical RAM to fully provision each of your VMs with 2GB. It is possible that you are seeing CPU contention - but I would expect that only if you have six heavily used VMs (even with them all having two vCPUs).

Ken Cline

Technical Director, Virtualization

Wells Landers[/url]

VMware Communities User Moderator