Q6-Q10

Q6. Is it possible to create a Virtual Machine using Azure Resource Manager in a Virtual Network that was created using classic deployment?

Q7. What are virtual machine scale sets (VMSS) in Azure?

Q8. Are data disks supported within Virtual Machine scale sets?

Q9. What is an Availability Set?

Q10: What is the difference between VMSS and Availability Set?

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Q6. Is it possible to create a Virtual Machine using Azure Resource Manager in a Virtual Network that was created using classic deployment?

Answer:

This is not supported. You cannot use Azure Resource Manager to deploy a virtual machine into a virtual network that was created using classic deployment.

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Q7. What are virtual machine scale sets (VMSS) in Azure?

Answer:

VMSS allows you to deploy and manage group of identical, load balanced VM as a single unit. VMSS can be created directly from Azure Portal. 

Key features: 

• autoscaling: Based on CPU metrics or any other custom metrics identicals VM can be added removed dynamically. 
• High Avaliablity
• Support Spots instances for cost effectiveness. 

Use Case:

• Autoscaling during high traffic periods like festivals. 
• Scale based on big data workload. If data size is big then increase no of VM doing the data processing. 
• Use Spot VMs for background tasks like batch order processing, reducing costs

There is NO cost of VMSS itself. 

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Q8. Are data disks supported within Virtual Machine scale sets?

Answer:

Yes. A scale set can define an attached data disk configuration that applies to all VMs in the set. Other options for storing data include:

Azure files (SMB shared drives)

OS drive

Temp drive (local, not backed by Azure Storage)

Azure data service (for example, Azure tables, Azure blobs)

External data service (for example, remote database)

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Q9. What is an Availability Set?

Answer:

An availability set is a logical grouping of VMs that allows Azure to place them in different Fault Domain and Update Domain to make HA and redundancy.  Availability Set is a concept of same Data Center, It's not distributed across Zones. 

Let say we have 6 VMs. 3 VMs for WebTier and 3 Vms for DB. So, to be sure that Web Tier all 3 VMs are down together, we can create an Availability set AV-Web and place all 3 Web VMs into that Availability set. Similarly for DB Tier. Azure will make sure that the VM of same Availability Set are down place in same Fault Domain and Update Domain. 

A Virtual machine can NOT be added to Availability Set once it is created. This discussion is to be taken at the time of VM creation. 

There is NO cost associated with Availability Set. You have to pay only for the VMs that are places in AS. 

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Q10: What is the difference between VMSS and Availability Set?

Answer:

VMSS:

1. Centralized management and configuration of multiple VMs together and keep them identical. 

2. Supports Auto Scaling (Schedule, Metrics, 

3. Supports spinning around Zones also together with Update Domain and Fault Domain. 

4. Azure Load Balancer can also deploy to connect the pool of identical VM we have in VMSS.  Application GW option will be present as well while creating a VMSS. 

Availability Set:

1. Manual configuration of all VMs in AS is required. eg If I want to install a software in VMs I have to do it manually in all VMs. 

2. Manual scaling is required. VM need to add at time of creation into AS. 

3. With in Data Centre. Only around Update Domain and Fault Domain. 

4. LB need to be deployed manually. 

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