Virtual Disks

• In Azure when we create a VM, We have two disk types
  • Os Disk:
    • This is will be mounted from a different Physical server where the vm was created from
    • Shutdowns and starts have no impact
    • We can delete the vm and still have the disk
  • Temp Disk:
    • This is will be mounted from same physical server where the vm was created from
    • This is slightly faster than os disk but the data over here is available as long as vm is running. Once the VM is stopped (deallocated), the disk will also be deallocated and when we start it back a new allocation might happen on altogether a new server (Physical), so this disk is considered temporary.
      
• The size of the Temp disk depends on the instance type or vm size selected
  

Virtual Machine Sizes

• Azure Provides different Sizes which can be chosen based on two factors
  • Purpose of your Virtual Machine
  • Once the purpose is decided, We have an option to choose VM Family by hardware specifications of the Physical Server.
• Purpose:
  • General Purpose:
    • Balanced CPU to Memory Ratio
  • Compute Optimized:
    • High CPU to RAM Ratio
  • Memory Optimized:
    • High RAM to CPU Ratio
  • Storage Optimized
  • GPU
  • HPC (High Performance Compute)
• Refer Here
  
• Azure VM Sizes Naming Convention Refer Here
  • Go through the examples.