Monthly Archives: January 2013

A Present from VMware

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Recently the number of VMware Certified Design eXperts (VCDXs) passed the 100 mark and to celebrate the wonderful VMware Education team decided to treat all VCDX’s.

Below are some photo’s of what I received late december which included

* A 6 pack of VCDX branded “Special Ale”
* A VCDX branded cooler bag
* Two VCDX Glasses
* A VCDX Sweater custom embroidered with my VCDX Number (#90)
* A VCDX polo shirt
* A HD Camcorder engraved with my VCDX number
* A Leeman Binder with my initials (see picture at bottom of this post)

and my favorite, a Vase with the VCDX logo along with my name and VCDX number on the base.

So just wanted to give a big Thank You to Mark Brunstad (@MarkBrunstad) and the VMware Education team for putting together this package for the VCDXs, I personally greatly appreciate it and you can rest assured the “special ale” did not see out 2012 🙂

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.