08-Azure Virtual Machines Flashcards
IaaS Shared Responsibility
Responsibility always retained by customer
Responsibility varies by service type
Responsibility transfers to cloud provider
Virtual Machine Planning
Start with the network
Name the virtual machine
Choose a location
Consider pricing
Virtual Machine Storage
Each Azure VM has two or more disks
OS and data disks reside in Azure Storage accounts
When creating an Azure V, you can choose between managed and unmanaged disks
Parameters to create Virtual Machine in Portal
Basics
Disks
Networking
Management
Advanced
Virtual Machine Connections
Bastion Subnet for RDP/SSH through the Portal over SSL
Remote Desktop Protocol for Windows-based Virtual Machines
Secure Shell Protocol for Linux based Virtual Machines
Windows VM Conections
Remote Desktop Protocol
WinRM
Linux VM Connections
Authenticate with SSH public key or password
SSH is encrypted connection protocol that allows secure logins over unsecured connections
There are public and private keys
Maintenance vs Downtime
Unplanned Hardware Maintenance
Unexpected Downtime
Planned Maintenance
Unplanned Hardware Maintenance
When platform predicts a failure, it will issue an unplanned hardware maintenance event
Unexpected Downtime
When a virtual machine fails unexpectedly
Planned Maintenance
Events are periodic updates made to the Azure platform
Availability Sets
Increase availability of Virtual Machine
Think as one single building with different racks, fault domains
Update domains
Allow Azure to perform incremental or rolling upgrades across a deployment.
During planned maintenance, only one update domain is rebooted at a time
Fault domains
Group of Virtual Machines that share a common set of hardware, switches, that share a single point of failure.
VMs in an availability set are placed in at least two fault domains
Availability Zones
Unique physical locations in a region
Includes datacenters with independent power, cooling, networking
Protects from datacenter failures
Combines update and fault domains
Provides 99.99% SLA
Take a single building and combine with two other buildings, total at least three buildings
Vertical scaling
increase or decrease power to a single instance of workload; usually manual
Horizontal scaling
increase or decrease number of instances of a workload; frequently automated
Implement Scale Sets
Instance count - # VMs in scale set (0 to 1000)
Instance size - size of each VM in scale set
Azure Spot Instance
Use managed disks
Enable scaling beyond 100 instances
Implement Autoscale
Define a minimum, maximum, and default number of VM instances
Create more advanced scale sets with scale out and scale in parameters
Virtual Machine Extensions
Small applications that provide post-deployment VM configuration and automation tasks
Managed with Azure CLI, PowerShell, Azure Resource Manager template
fill in
Custom Script Extensions
Simple or complex
Has 90 minutes to run
Double check dependencies to ensure availability
Account for any errors that might occur
Protect/encrypt sensitive information
Desired State Configurations
Configuration block(s) have a name
Node blocks define the computers or VMs that you are configuring
Resource block(s) configure the resource and its properties
There are many built-in configuration resources
