How much CPU ready is OK?

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I have noticed a lot of search results hitting my blog asking

Question: How much CPU ready is OK?

so I thought I would address this question with a quick post.

Of course the answer is it depends, for example Server workloads have a lower tolerance to CPU ready than desktop workloads but as a rule of thumb, here is my thoughts.

For Production server workloads

<2.5% CPU Ready
Generally No Problem!

2.5%-5% CPU Ready
Minimal contention that should be monitored during peak times

5%-10% CPU Ready
Significant Contention that should be investigated & addressed

>10% CPU Ready
Serious Contention to be investigated & addressed ASAP!

In my experience, the above have been good for a rule of thumb.

However, applications which are latency sensitive may be severely impacted even with low levels of CPU ready, these types of VMs should be on clusters with lower CPU overcommitment, leverage DRS rules to separate the contending workloads or in extreme cases, dedicated clusters.

On the flip side, Some servers are much more tolerant to CPU ready, and 5%-10% CPU ready or higher may not noticeably impact performance.

Keep in mind that setting CPU Reservations does not solve CPU Ready, see my post on the topic for more details.

VMware vCenter Operations is a tool which can help easily identify contention (including CPU) within your vSphere environment.

For Virtual Desktop workloads, what level of CPU ready is acceptable will largely depend on the individual user (ie: Power User verses Task Worker). Keep in mind virtual desktop deployments generally have high CPU consolidation ratios of  around 6:1 all the way to >12:1.

I would suggest the following , again as a rule of thumb

<5% CPU Ready
Generally No Problem!

5%-10% CPU Ready
Minimal contention that should be monitored during peak times

>10% CPU Ready
Contention to be investigated & addressed where the end user experience is being impacted.

Any Higher CPU ready will likely be impacting your users, and should be investigated.

VMware have recently released vCenter Operations for View, which you could use to monitor your VMware View environment.

Nested ESXi 5.1 on IBM x3850 M2 (7141-xxx model)

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For my test lab I use an IBM x3850 M2 model 7141-3RM. Its a 4 socket server, with 4 cores per socket and 96Gb Ram running nested ESXi hosts.

Until recently, I was still running ESXi 5.0 on the physical host, with nested ESXi 5.1 hosts which worked perfectly.

Recently I decided to upgrade the physical host to ESXi 5.1.

Problem: My nested ESXi 5.1 hosts can no longer run 64bit VMs.

Now why is that? The Intel E7330 supports Intel-VT-x w Extended Page Tables (see Intel’s website here) or so they say?!

IntelEssentials IntelAdvancedTech

As mentioned by William Lam (@lamw) on his blog (VirtuallyGhetto)

A quick way to verify whether your CPU truly supports both Intel-VT+EPT or AMD-V+RVI, you can paste the following into a browser:

https://[your-esxi-host-ip-address]/mob/?moid=ha-host&doPath=capability

So, after running this on my host, I got the following result

nestedHVsupport

So that’s a bummer, I cant run ESXi 5.1 on my physical host with nested ESXi hosts running 64 bit VMs.

Note: 32bit VMs run fine.

So, Intel are telling fibs about what this processor can do, but that doesn’t help solve the issue.

Solution: If you have this processor in your test lab and/or have the IBM x3850 M2 model 7141-xxx (or you obtain one as they are a great low cost option for a test lab) run ESXi 5.0 on the physical host, and run ESXi 5.1 nested and you can run 64bit VMs.

Storage Capabilities not appearing after Installing & configuring the Netapp VASA Provider 1.0

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When installing the Netapp VASA provider 1.0 today, I was surprised to find the Storage Capabilities were not being populated (as shown in the screen shot below). As I have installed and configure the Netapp VASA provider numerous times and never had an issue, this was very annoying.

StorageCapabilitiesBlank

 

I had completed the configuration of the VASA provider (see below) and successfully registered the provider.

netappvasaconfig_blank

I confirmed the provider was showing up by going to the “Solution providers” in vSphere Client

NetappVASASolutionProviders

Then confirming the vendor provider has been registered as per the below.

VendorProviders

So after unregistering the provider then uninstalling and re-installing the Netapp VASA Provider software the problem was still not solved.
After a quick Google, much to my surprise I couldn’t find anything on this issue.

It turns out, it was a quite simple “fix” if I can call it that.

For whatever reason I configured the storage system first, then proceeded to complete the other steps.

If your having this issue, you can avoid the problem by configuring the VASA provider (shown below) in this order

1. Configure the username and password for communication with vCenter
2. Configure the vCenter server details and register the provider
3. Register the storage system

 

netappvasaconfig

 

Shortly there after the storage capabilities all appeared successfully.

StorageCapabilitiesWorking

So the above contradicts the official Netapp installation guide for the VASA provider, which states on P11 that you can add storage systems at any time,  but solved my problem.

Hope you found this useful.