The VM Reservation and Limits card was released yesterday. CloudPhysics decided to create this card based on the popularity of this topic in the contest. So what does this card do? Let’s have a closer look.

This card provides you an easy overview of all the virtual machines configured with any reservation or limits for CPU and memory. Reservations are a great tool to guarantee the virtual machine continuous access to physical resources. When running business critical applications reservations could provide a constant performance baseline that helps you meet your SLA. However reservations can impact your environment as the VM reservations impacts the resource availability of other virtual machines in your virtual infrastructure. It can lower your consolidation ratio: The Admission Control Family and it can even impact other vSphere features such as vSphere High Availability. The CloudPhysics HA Simulation card can help you understand the impact of reservations on HA.
Besides reservations virtual machine limits are displayed. A limit restricts the use of physical access of the virtual machine. A limit could be helpful to test the application during various level of resource availability. However virtual machine limits are not visible to the Guest OS, therefor it cannot scale and size its own memory management (or even worse the application memory management) to reflect the availability of physical memory. For more information about memory limits, please read this post by Duncan: Memory limits. As the VMkernel is forced to provide alternative memory resources limits can lead to the increased use of VM swap files. This can lead to performance problems of the application but can also impact other virtual machines and subsystems used in the virtual infrastructure. The following article zooms into one of the many problems when relying on swap files: Impact of host local VM swap on HA and DRS.
Color indicators

As virtual machine level limits can impact the performance of the entire virtual infrastructure, the CloudPhysics engineers decided to add an additional indicator to help you easily detect limits. When a virtual machine is configured with a memory limit still greater than 50% of its configured size an Amber dot is displayed next to the configured limit size. If the limit is smaller or equal to 50% of its configured size than a red dot is displayed next to the limit size. Similar for CPU limits, an amber dot is displayed when the limit of a virtual machine is set but is more than 500MHz, a red dot indicates that the virtual machine is configured with a CPU limit of 500MHz or less.
For example: Virtual Machine Load06 is configured with 16GB of memory. A limit is set to 8GB (8192MB), this limit is equal to 50% of the configured size. Therefore the VM reservation and Limits card displays the configured limit in red and presents an additional red dot.

Flow of information
The indicators are also a natural divider between the memory resource controls and the CPU controls. As memory resource control impacts the virtual infrastructure more than the CPU resource controls, the card displays the memory resource controls at the left side of the screen.
We are very interested in hearing feedback about this card, please leave a comment.
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This article shows you how to create a VM to Host affinity rule using the new webclient.
1. Select host and clusters in the home screen.
2. Select the appropriate cluster.
3. Select the tab Manage and click on Settings.

4. Click on the >> to expand the Cluster setting menu.

5. Select DRS Groups.
6. Click on Add to create a DRS Group.
The dropdown box provides the ability to create a VM DRS group and a Host DRS group. The behavior of this window is a little tricky. When you create a group, you need to click on OK to actually create the group. If you create a VM DRS group first and then select the Host DRS group in the dropdown box before you click OK, the VM DRS group configuration is discarded.

7. Create the VM DRS Group and provide the VM group a meaningful name.
8. Click on “Add” to select the virtual machines.
9. Click on OK to add the virtual machines to the group.

10. Review the configuration and click on OK to create the VM DRS Group.
11. Click on “Add” again to create the Host DRS Group.
12. Select Host DRS Group in the dropdown box and provide a name for the Host DRS Group.
13. Click on “Add” to select the hosts that participate in this group.
14. Click on OK to add the hosts to the group.

15. Review the configuration and click on OK to create the Host DRS Group.
16. The DRS Groups view displays the different DRS groups in a single view.

The groups are created, now it’s time to create the rules.
17. Select DRS Rules in the Cluster settings menu.

18. Click on “Add” to create the rule.

19. Provide a name for this rule and check if the rule is enabled (default enabled)
20. Select the “Virtual Machines to Hosts” rule in the Type dropbox.
21. Select the appropriate VM Group and the corresponding Host Group.
22. Select the type affinity rule. For more information about the difference between should and must rule, read the article: “Should or Must VM-Host affinity rules?”. In this example I’m selecting the should rule.
23. Click on Ok to create the rule.
24. Review your configuration in DRS rules screen.

Get notification of these blogs postings and more DRS and Storage DRS information by following me on Twitter: @frankdenneman

Disclaimer: I’m a technical advisor for CloudPhysics.
I’m very happy to see CloudPhysics coming out of stealth mode this week and making their beta product available to the public. In a nutshell CloudPhysics is bringing Big Data analytics to the IT environment and it will provide you with tools to analyze your datacenter. How does it acquire this dataset and what benefit do you get from it?
The Observer Appliance
To gather all that data, an Observer Appliance needs to run in the virtual infrastructure. And in order to get a valuable dataset that is used for analytics and simulations the Observer needs to be active in as many as virtual infrastructures as possible. Running an appliance that sends operational data to a third party like CloudPhysics can be a security concern. Going into detail about how CloudPhysics designed the system to handle privacy, security and data sharing issues is outside the scope of this article. In short, data extracted from the virtual infrastructure are performance statistics and inventory and configuration settings. All environmental details are scrubbed and no log files or content of disk and memory is gathered.

The User Interface
The data acquired by the Observer Appliance is accessible at https://app.cloudphysics.com. Logging in will give you access to your own data. The beta product provides a user interface that allows you to dive into specific focus areas. The UI provides so-called cards that displays key data points and is a launch point to a more detailed view. This view can contain information about the relationship with other features of the vSphere stack. An example of such a card would be Virtual Machine level reservations. Not only does this card provide you information about the present virtual machine level reservations in your environment in a clear and concise manner, it also displays the impact the reservation has on the High Availability slot size and therefor the consolidation ratio of your cluster. All this information combined in a single screen, no need to navigate through multiple screens and correlate particular metrics.

Correlation of metrics
Correlation of particular settings and understanding the impact each setting has on a complex environment, such as a virtual infrastructure, is time consuming and above all very difficult. This correlation of metrics allows you to save time, but it also helps you understand behavior of your environment. Now you might ask how do you know you can trust if these correlations are correct and this is one of the most interesting things about this product. It’s a combination of product expertise and community driven input.
The two pillars of knowledge
The CloudPhysics team comprises of industry heavy hitters. Some of these persons invented core features of the vSphere stack while working for VMware, while others made their mark at other industry leading companies. The second pillar is the community involvement. In this beta program, registered users can suggest ideas for utility cards. Domain experts will verify the community provided cards on technical accuracy.
Near-future developments
One thing I’m very exited about is the upcoming High Availability and DRS simulation tools. Both HA and DRS can be a challenge to configure as some settings impact the virtual infrastructure on multiple levels. The HA and DRS simulation analyzes current settings and provides you a platform where you can predict the effects of a change on your environment.
VMworld Challenge 2012
Now back to the current status. CloudPhysics is running a VMworld Challenge 2012. The contest allows you to describe the problems you are facing, such as “I’m applying different disk shares in my environment but I cannot see the worst case scenario allocation”. The more card you produce, the more points you score. To increase your score, download the Observer Appliance and take your environment for a test drive. The more activity you generate, the more points you accumulate. How will you benefit from this contest, first of all, if you are located in the U.S. you can win some great prices. (Due to U.S legislation, non-U.S. residents are excluded from winning prizes), but by submitting cards you improve the system and the quality of the reporting tool and simulation tool.
Resource Management as a Service
I started of with a disclaimer, I am a technical advisor to CloudPhysics and you can expect to see more articles about the development of CloudPhysics. As I’m able to work with the inventors of DRS and Storage DRS, a lot of my focus is on resource management. Together with the input of the community, the continuous analysis by domain experts you can expect that this might well turn out as Resource Management as a Service.