I have created two vm's in azure and assigned an availability set.
But in the overview I see that both the vm's are assigned under same Fault Domain.
Should the vm (Vm availability-test-vm2) have been assigned to Fault domain 1 instead of 0 ?
By default, the virtual machines configured within your availability set are separated across up to three fault domains for Resource Manager deployments.
If there are only two VMs within an availability set, each VM should be in a different fault domain. However, If there are more than two VMs(for example, 3 VMs in 2 fault domains) or you have created three VMs(even you delete one of them), it's possible that the remaining 2 VMs are assigned to the same fault domain because the original three VMs should be in fault domain 0, 1, 0.
For example,
You can create and deploy virtual machines in an availability set using Azure PowerShell. Please note that A VM can only be added to an availability set when it is created.
Related
When deploying AKS cluster into different availability zones ("1,2,3" in our case) the vm scaleset is used for default nodepool deployment (not availability set). Everything is pretty fine there, but the problem is - while using the default nodepool scaleset, it is put into 1 fault domains only, and i did not find a way to change that (despite the fact, that the vm scaleset should be deployed into 5 fault/update domains as per documentation):
Why is it so ? How to put the nodepool into default 5 fault/update domains in addition to 3 availability zones (i mean 5 fault/update domains in each of the 3 availability zones)?
P.S. - You can always deploy AKS cluster's nodepool into availabilitySet, and have 5 update/fault domains, but then the availability zones are not available when using the availabilitySet.
By reference to this doc: Choosing the right number of fault domains for virtual machine scale set, for the regions that support zonal deployment of virtual machine scale sets and this option is selected, the default value of the fault domain count is 1 for each of the zones.
You can also consider aligning the number of scale set fault domains with the number of Managed Disks fault domains.
So I have 2 classes of VM. Lets call them serverA and serverB.
Within my availability set I want to make sure each Fault domain has 1 of each VMs (ServerA and ServerB). Is it possible to have this level of fine control? From what I can tell it looks like this is achieved by adding the Servers in a specific order i.e. serverA, server A, server B server B assuming I had 2 fault domains.
Is this true? Is it the only way?
When you deploy Virtual machines in an Availability Sets, Azure takes care of placing machines in different fault domains and update domain. We do not have granular level control on deciding which VM needs to be in which Fault domain.
In a high level, if you deploy 2 VMs, then Azure will make sure those 2 VMs are part of different Fault domain and update domain.
I provisioned a few Azure VM's in an Availability set using the Azure Java SDK. The VM deployed successfully and is running. However, one of the VM's, the one provisioned first, does not display a fault domain or an update domain.
Why is my VM not being assigned a fault domain or an update domain?
Why is my VM not being assigned a fault domain or an update domain?
No, your VM is in an availability set. Your availability set name is SG-*. When VM in an availability set, it will assign a fault domain and update domain automatic.
You could get your VM's fault domain and update domain value on Azure Portal.
Resource group-->Availability set-->Virtual Machines
Update:
However, one of the VM's, the one provisioned first, does not display
a fault domain or an update domain.
Based on my knowledge, it is a design behavior. The first VM's fault domain and update domain is 0 0. You could all domain on Availability set.
I read the following in the AZURE214x Azure Fundamentals openedx course:
Each virtual machine in an availability set is placed in one update
domain and two fault domains.
I don't understand why a VM in an availabilty set is placed in two fault domains? I mean a VM can only sit in one fault domain or am I wrong? Can someone explain?
Each virtual machine in an availability set is placed in one update
domain and two fault domains.
No, this is wrong.
Each virtual machine in your availability set is assigned an update domain and a fault domain by the underlying Azure platform.
Also, you could refer to Mistake in Module3, Review question 2 (AZURE202x Microsoft Azure Virtual Machines).
I guess its just a wording thing, VM cannot be in 2 fault domains at the same time.
"Each virtual machine in your availability set is assigned an update domain and a fault domain by the underlying Azure platform."
Reference: https://learn.microsoft.com/en-us/azure/virtual-machines/virtual-machines-windows-manage-availability
I want to add traffic manager to my azure virtual machine.I created total 4 virtual machine .2 in east us region and 2 in north Europe region.but when i want to add the both 2nd machine in the availability set respectively i didn't find the other machine which i want to add.
so help me to configure this
Availability Sets and Traffic Manager are not related subjects in Azure. When you create your two virtual machines in each Region make sure to add them to the same Cloud Service. This will enable load balancing and enforce availability set behaviour across the two VMs.
Repeat this in the second Region.
Then use Traffic Manager to route traffic using a Failover strategy (if appropriate) to the public interfaces of the Cloud Services.
While this is about using Web Roles you might find this blog series useful: http://blog.kloud.com.au/2014/11/03/deploy-an-ultra-high-availablity-mvc-web-app-on-microsoft-azure-part-1/
Availability sets are not the same as the traffic manager.
Availability sets are per region (that's why you only see 2 machines)
Add a traffic manager through the portal and select the VM's in both regions.
http://michaelwasham.com/windows-azure-powershell-reference-guide/understanding_configuring_availability_sets_powershell/
https://alexandrebrisebois.wordpress.com/2013/07/23/windows-azure-traffic-manager-high-performance-availability-resiliency/