Giving Back to the VMware community

After achieving my VCDX in Toronto mid last year (2012), one of my goals was to start blogging and giving back to the VMware/Virtualisation community which I wrote in my About Me post back in April last year.

Over the last year I presented at multiple VMUG events , contributed to community podcasts and kicked off this blog (CloudXC). I also got more involved with Twitter and VMware Communities forum.

I have also helped a number of VCDX candidates with mock panels and submission reviews and I am very pleased a number of those candidates have been successful.

I am pleased to say I have thoroughly enjoyed getting more involved with the community, and have met a lot of great people and learnt lots of new things along the way.

Today I received notification that along with 574 others, I was awarded the title of vExpert for 2013. (vExpert Awardees announced here)

Just like achieving VCDX, earning the vExpert title for me is just motivation to continually keep improving my skills and adding value to the community.

Thanks to everyone involved with the vExpert Program and I look forward to continuing to contribute too this great community and hopefully get another vExpert gong next year.

Congrats to everyone else who was awarded vExpert for 2013!




Example Architectural Decision – Advanced Power Management for vSphere Clusters with Business Critical Applications

Problem Statement

In a vSphere environment where Business Critical Applications have been successfully virtualized, should Advanced Power Management be used to help reduce data center costs?


1. Fully Supported solution

2. Reduce data center costs where possible

3. Business Critical Application performance must not be significantly degraded


1. Supported Hardware

2. vSphere 5.0 or later

3. Admission Control is enabled with >= N+1 redundancy


1. None


1. Reduce Datacenter costs where possible with minimal/no impact to performance

Architectural Decision

Configure the BIOS to “OS Controlled”

Set ESXi Advanced Power Management to “Balanced”


1. Power savings can be realized with almost no impact to performance

2. The performance difference between “High performance” & “Balanced” options is insignificant however Power savings can be achieved reducing cost and environmental impacts

3. In the unlikely event of performance issues as a result of using the “Balanced” option, the BIOS is set to OS Controlled so ESXi can be updated without downtime during troubleshooting

4. Advanced Power Management Options (other than “High Performance” & “Balanced”) have proven to have excellent power savings but at a high cost to performance which is not suitable for Business Critical Applications

5. As HA Admission Control is used to provide >=N+1 redundancy, the ESXi hosts will generally not be fully utilized which will give Advanced Power Management opportunities to conserve power

6. The workloads in the cluster/s run 24/7 however demand is generally higher during business hours and some low demand or idle time exists

7. Even where only a small power saving is realized, if performance is not significantly impacted then a faster ROI can be achieved due to cost savings


1. Where performance issues exist using “Balanced” a vSphere administrator may need to change Advanced Power Management to “High Performance”


1. Use “High Performance”

2. Use “BIOS Controlled”

3. Do not use Advanced Power Management

4. Use Advanced Power Management in conjunction with DPM

Relates Articles

1. Power Management and Performance in ESXi 5.1 – By Rebecca Grider (@RebeccaGrider)



Example Architectural Decision – Jumbo Frames for IP Storage (Do not use Jumbo Frames)

Problem Statement

When using IP based storage over a converged 10GB network, should Jumbo Frames be used?


1. Fully Supported storage

2. Maximum vSphere environment availability

3. Maximize performance where possible


1. Converged 10GB Network which is highly available

2. Two (or more) 10GB connections per ESXi host


1. No dedicated network for IP storage traffic


1. Simplify the environment

Architectural Decision

Do not use Jumbo Frames


1. Reduce the complexity in the environment for initial implementation

2. Simplify ongoing support / troubleshooting

3. For a Jumbo Frame to be transmitted without fragmentation, All devices end to end must support and be configured for Jumbo Frames

4. While there can be performance benefits of Jumbo Frames for IP Storage this is not generally seen across the board and depends on I/O types

5. Ensure IP storage packets are not fragmented or dropped by mis-configured devices or devices that do not support Jumbo Frames

6. Storage performance for the virtual environment will generally be constrained by the storage array controllers not the storage area network

7. Ensure packet fragmentation does not occur as all devices support a default MTU of 1500

8. Increasing the MTU will decrease the number of packets required for the same bandwidth but where the bottleneck is throughput (bytes) there will be minimal/no benefit

9. Jumbo Frames will only assist where the network is constrained at an interrupt level


1. IP Storage may have reduced performance in some circumstances compared to what Jumbo Frames may offer


1. Use Jumbo Frames

Relates Articles

1. Example Architectural Decision – Jumbo Frames for IP Storage (Use Jumbo Frames)


Thanks to Rob McNab (IBM) and Peter McCrystal (IBM) for their input into this example architectural decision.