Become a labITpro Supporter

Registration Details

Provide your account details below.

Your account can have multiple subscriptions attached to it so there is no need to abandon your current subscriptions.

E-mail *

First Name

Last Name

Password *

Repeat Password *

Please notify me of new labs and special discounts on IT training courses.

labITpro Supporter - $4.99
For a nominal one-time fee, labITpro Supporters can launch the Base Collection labs and Skillbuilder Labs immediately without watching lab videos. labITpro Supporters also get an ad-free experience, access to step-by-step lab instructions where available, access to Ask the Author, and access to the private labITpro Community forum.
Select a Payment Method
PayPalCredit / Debit Card
No payment methods are available for the selected subscription plan.
Discount Code:
Applying discount code. Please wait...

Payment Details

What’s Included

38 Labs Total

Includes the 12-lab Base Collection + 26-lab Skillbuilder Collection.

Skip the Videos!

Launch labs instantly without sitting through lab videos.

Ad-Free Experience

Learn without interruptions or promotional screens.

Ask the Author

Get direct help when you’re stuck or need guidance.

Community Forum Access

Connect with other learners and share solutions.

One-time payment of $4.99. No renewals. Lifetime access to everything above.

This feature is available to labITpro Supporters only.

Azure VM Scale Sets — Quick Reference

Fast lookup for orchestration modes, autoscaling, load balancing, updates & CLI.

Core Benefits

Create & manage groups of identical or heterogeneous VMs.
Automatic scaling based on demand or schedule.
Load balance traffic across instances.
HA across fault domains & availability zones.
Pay only for VMs; no charge for scale set itself.

Scale sets can handle up to 1,000 VMs (Marketplace/Gallery images).

Orchestration Modes

Mode	Profile	Best For
Flexible	Standard Azure VMs	New workloads (default)
Uniform	Identical VMs	Legacy large-scale workloads

Flexible: Full standard VM APIs, dynamic mixing (Spot+on-demand), 1,000 VMs. Uniform: Locked after creation; up to 1,000 VMs (Marketplace) or 600 (custom images).

Orchestration Comparison

Feature	Flexible	Uniform
Standard VM APIs	Yes	No
Mix instance types	Yes	No
RBAC per VM	Yes	No
Azure Backup	Yes	No
Site Recovery	Yes	No
Fault domains	1–3	1–5

Autoscaling Metrics

Host metrics: CPU, memory, disk (no agent needed).
Guest metrics: Custom counters (Azure Diagnostics Extension).
App Insights: Application-level performance metrics.
Rules: Min/max capacity, scale-out/in thresholds, cooldown periods.

Autoscale rules use metrics from Load Balancer, Diagnostics, or App Insights.

Load Balancing

Type	Layer	Best For
Internal LB	L4	Backend pools
Public LB	L4	External traffic
App Gateway	L7	HTTP/HTTPS + WAF

Large scale sets (>100 VMs) require Load Balancer Standard SKU.

Availability & Zones

Single zone: All VMs in one availability zone.
Zone-redundant: VMs spread across 1, 2, or 3 zones in region.
Zone balance: Auto-spread VMs evenly across zones (±1 VM).
Fault domains: 1–3 per zone for best-effort resilience.

Use availability zones for datacenter-level failure protection.

Upgrade Policies (Uniform)

Policy	Rollout	Use
Automatic	Batch	App can tolerate disruption
Rolling	Controlled	Gradual, managed updates
Manual	On-demand	Full control; explicit API calls

Flexible mode uses standard VM updates; no built-in rolling.

Application Deployment

Custom image: Preinstall app; faster provisioning.
Custom Script Extension: Download & run scripts post-deploy.
Azure VM Applications: Package & manage centrally (new).
PowerShell DSC: Desired State Configuration for consistency.

Custom images: 600 VMs max; Marketplace images: 1,000 VMs.

Planned Maintenance & Health

Azure Patch Manager: Automated guest OS patching.
Application Health Extension: Monitor app heartbeat; auto-replace unhealthy.
Health probes (Uniform): Monitor via load balancer.
Platform updates coordinated; typically brief interruption.

Become a labITpro Supporter

Registration Details

Select a Payment Method

Payment Details

Azure VM Scale Sets — Quick Reference

Core Benefits

Orchestration Modes

Orchestration Comparison

Autoscaling Metrics

Load Balancing

Availability & Zones

Upgrade Policies (Uniform)

Application Deployment

Planned Maintenance & Health

An Introduction to Microsoft Entra ID

Azure Files in Under a Minute

Azure vNets Explained

Ask The Author

VMs Made Easy: A Deep Dive Into All VM Settings