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vmSternman
Contributor
Contributor

ESXI 4 CPU Usage jumping every few minutes, guests VM's not

Hello;

I have esxi 4 installed on a sun V20Z box with 2x CPU's and 2GB ram.

This box has 2x 73gb scsi drives running RAID 1 through the on board controller. On these disks, is where esxi is installed and both of my vm's.

I have added to this system an LSI MegaRAID SATA 300-8XLP card with 5 SATA drives running.

The two VM's are OpenFiler (has control over all of the drives off of the Sata raid card) and Trixbox.

OpenFiler has allocated to it, 1024MB ram and Trixbox has 512 MB ram.

Now, I notice that each of the two VM's use very little cpu power when idle, however, the host esxi box is reporting max cpu usage spikes every few minutes.

I set reservations to the vm's in hopes of quelling the host from using all of the cpu power in these strange intervals.

The image attached shows the story of the picture I am trying to paint.

I dont know where to look in order to figure out why the esxi is reporting such high and interval-ed cpu usage.

When I look at the system performance graph, i can see that the esxi system appears to be using the cpus at these intervals.

Is this normal?

Should I be concerned, and if so, how can I resolve this?

Thank you

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6 Replies
puneetgupta
VMware Employee
VMware Employee

Hi,

Do you observe any performance degradation with your VMs also?

To rule out any other VM resource usage, is it possible for you to migrate these VMs to some other ESX host and see if you still observe the same behaviour on the running system.

I am assuming you are not running any script on your host which could be creating this. Please confirm.

Thanks.

vmSternman
Contributor
Contributor

Hi;

I can look into moving the VM's to another host.

I have not tested the VM's extensively to notice any performance degrading. Since one is a NAS box (I might be able to tell through max throughput) and the other is a phone system, they are both not resource intensive applications.

The esxi install is standard. I installed it, and then logged in through the vsphere client only.

As far as I know, there are no scripts running on the VMware host.

I will shut off the vm's to see if the issue persists. If it goes away, I will test each of the VM's on another esxi box separately.

I like this approach, thank you.

I will let you know the outcome of all three procedures.

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DSTAVERT
Immortal
Immortal

I would suggest that with so little RAM in this ESXi host that performance will ALWAYS be an issue. Trying to adjust anything will further complicate matters. I can't look it up but I think 2GB RAM is the minimum for installing ESXi exclusive of virtual machines.

-- David -- VMware Communities Moderator
vmSternman
Contributor
Contributor

Ok.

So, I stopped the two VM's. I did not notice any change in the CPU graph.

I rebooted the esxi host. When it came backup, I let it sit idle for about 10 minutes. The cpu spikes did not recur.

I started one of the vm's. I let it sit for 10 minutes, the spikes did not recur.

I started the second vm, I let it sit for 10 minutes, no spikes.

I waited an hour, and still, no spikes.

So, I dont know what caused it, but, it appears to have waned with a reboot.

I will monitor the situation and in the mean time, I have ordered more memory for the system.

Thank you for you help.

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puneetgupta
VMware Employee
VMware Employee

Thanks. Feel free to report your findings further.

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vmSternman
Contributor
Contributor

Hi puneetgupta;

I fully intend to.

What i did find, to corroborate the information regarding minimum memory provided by DSTAVERT, under Configuration -> System Resource Allocations -> Advanced, there exists a memory reservation for the host of 1674MB. Given that my system has 2GB total and I would like to allocate 1.5GB to the VM's, I dont have enough and with time, I imagine this is the cause of the issue that I found. (i dont know for sure, i may not know).

Right now, things are back to normal, and I will be watching the situation closely for a few weeks to see if that changes.

As well, I have ordered more RAM for this system and 1 other esxi box I have with 2GB ram.

Since, it appears, that is not enough.

Thank you both for your help.

vmSternman

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