time to show you what else you can do with views and reports and a very cool feature the what if scenario.
Capacity Reports and What if Statements
This is the business end of Capacity Management which is being able to provide people with the black and white figures for what is remaining and to show what can and can’t fit in the current environment or cluster.
First we will look at what if statements, What if statements are used if you have a project manager come over to your desk and said is there enough resources for the 10 VMs I need to provision for Project X. So what do we do next?
1) First off we need to go to the planning tab and under views or summary you should see the what if box on the bottom right. Click on the what if link as shown in the image below.
2) Once selected you should now how the what if dialog box open, asking what type of change you would like to make. Similar to the image below. For the demo we are doing we will first select Virtual machine option.
3) Once we have selected virtual machines and clicked next we then need to pick what we would like to do, Add virtual machines with custom profile, Add virtual machines based on existing virtual machines as models or remove virtual machines. Similar to what is shown below in the image.
4) For this example we will be choosing the first one which is Add virtual machines by specifying the profile of the new machines. Once selected hit next and you will see the configuration screen as shown in the below image.
On this screen we can configure the following:
• Number of Virtual machines
• vCPU configuration including utilisation, limit and reservations
• vMemory configuration including utilisation, limit and reservations
• Disk configuration including number of disks, type and usage
For this example we will be selecting 10 VMs, each with 2 vCPUS and we are going to estimate that the virtual machines will use an average of 50%.
The memory configuration will be 2GB at an 80% usage. Both the CPU and memory won’t have reservations.
We will not enter any storage data, Storage is one of those setting you can use if your environment is suited for it. Most enterprise environments storage is generally handled by a separate team and is provisioned on an as needed basis.
If you look on the right pane you will see you current population summary, with what vCOPS has worked out as small medium and large profiles, which you can use as a guide if you would like.
Note – The more accurate you can make the profile the more accurate the prediction will be.
5) Once you are happy with the settings of the new virtual machines the project manager has asked for, click next. We are now presented with the summary page as shown below in the image. This lists what our what if configuration will be. Time to click finish and see how out environment looks.
6) We no go back to the view we were looking at originally but now it has what the current capacity is and what the predicted capacity is if we were to add those 10 virtual machines. If you look at the image below you can see the two columns one saying actual and the other saying added 10 VMs. You wil notice not only is the memory even more over the limit than before but the CPU is now the number 1 constraining factor taking us from having 1.3 virtual machines available to being over by 17.
The main factor for this was the usage settings we made in the what if statement.
Now what can we do now we need to give that project manage something to take away besides no we cant fit those 10 virtual machines in the current environment. SO how about we also tell him how many extra hosts will have to be bought to cater for the project.
7) So this time we click on the what if scenario again but this time select the hosts and data store options, and add an additional host, configure t to the same configuration as your existing hosts.
8) Hit next and you will see the review screen. make sure its all good and hit finish.
9) Now we can see that we have both the 10 VM and the hardware changes, these both use the Actual as the base and are independent of each other.
10) Under the 2 scenarios on the right you can see the the compare with the drop down button, select this can choose combine, What this does is combine all the scenarios so in our case it will be taking the actual and adding 10 VMs and an additional host.
Now we can tell that PM we will require 2 new hosts to fit his project on the cluster.