Admission control is part of vSphere High Availability (HA). It enforces and ensures availability in case of host failures. It guarantees that there is enough cluster capacity (memory or CPU) left for a HA failover by preventing VM power on actions that would violate that guarantee.
Since vSphere 6.5 there’s a dynamic calculation of minimum required resources, depending on your host number and host failures you want to tolerate.
Let’s start with an example: A cluster got two equal hosts and should tolerate one host failure. Admission control will make sure that neither CPU, nor memory load will exceed 50% of your total resources. If you lose one host there will be enough resources to restart VMs on the remaining host.
Let’s imagine you’re adding another two hosts to the cluster. The number of host failures to tolerate is still 1, but now dynamic resource calculation kicks in. With now four hosts, admission control will allow you to fill up the cluster to 75% before it will prevent VM power on.
That’s great. Because you just have to define your desired number of host failures to tolerate and HA admission control will dynamically calculate the allowed percentage of cluster resources to use. It works for adding and removing hosts likewise.
There’s an upgrade track from VCP6-NV to VCP-NV 2019 without taking an exam. It’s not easy to find this possibility. I will show all necessary steps to take and would like to thank Tim Burkhard (VMware Education Team), who pointed me into that direction.
First you go to VMware-Education and choose the VCP-NV 2019 track. Depending on your current certification status track requirements will be different. Only if you’re holding a current VCP6-NV certification, you’re able to upgrade without an exam. All others will have to pass the exam.
Choose VCP6-NV in the dropdown menu and read the requirements.
Do you like VMware Hands-on-Labs? I bet you do! If you’re coming to VMworld 2019 Barcelona you can prove your skills in an awesome competition and maybe become an Odyssey Champion.
Form a team with up to 3 members or join an existing team and compete with other teams in the VMware Odyssey Cup. There will be 24 teams all together and they have to complete tasks in Hands-on-Labs. Teams will be judged by accuracy and time to complete the tasks in the lab. There’ll be labs about vSphere, vSAN, Horizon and vRealize Automation. You’ll need some free time slots in your VMworld schedule on Tuesday and Wednesday and if you’re successful for the finals on Thursday.
Tuesday, November 5, 2019 | 3:00 PM – 4:30 PM
Wednesday, November 6, 2019 | 3:00 PM – 4:30 PM
Thursday, November 7, 2019 | 10:30 AM – 12:00 PM
Members of the winning team will get a new MacbookPro. The second best team will get an OculusGo for each member and every participant will get a cool Odyssey jacket.
Interested? Then hurry up and register for VMware Odyssey by Hands-on Labs. It’s also possible to register on site at the Odyssey info desk on Monday.