azure-vm-scalesets

Azure Virtual Machine Scale Sets Skill

This skill provides expert guidance for Azure Virtual Machine Scale Sets. Covers troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. It combines local quick-reference content with remote documentation fetching capabilities.

How to Use This Skill

IMPORTANT for Agent: Use the Category Index below to locate relevant sections. For categories with line ranges (e.g., L35-L120), use read_file with the specified lines. For categories with file links (e.g., [security.md](security.md)), use read_file on the linked reference file

IMPORTANT for Agent: If metadata.generated_at is more than 3 months old, suggest the user pull the latest version from the repository. If mcp_microsoftdocs tools are not available, suggest the user install it: Installation Guide

This skill requires network access to fetch documentation content:

• Preferred: Use mcp_microsoftdocs:microsoft_docs_fetch with query string from=learn-agent-skill. Returns Markdown.
• Fallback: Use fetch_webpage with query string from=learn-agent-skill&accept=text/markdown. Returns Markdown.

Category Index

Category	Lines	Description
Troubleshooting	L37-L43	Diagnosing and fixing issues with VMSS instance mix, standby pools behavior, and autoscale (rules, scaling delays, capacity mismatches, and common error scenarios).
Best Practices	L44-L49	Configuring rolling upgrades for VM scale sets, tuning MaxSurge settings, and strategies to minimize downtime and maintain high availability during production updates.
Decision Making	L50-L66	Guidance on choosing VMSS orchestration/upgrade modes, autoscale, Spot vs standard/priority mix, fault domains, standby pools, and cost-optimized configurations for different workload patterns.
Architecture & Design Patterns	L67-L71	Designing scale sets with proximity placement groups to minimize latency, improve performance, and ensure VMs are co-located for tightly coupled or high-performance workloads
Limits & Quotas	L72-L77	Limits, quotas, and behaviors of VM Scale Sets, including placement groups, max instance counts, capacity constraints, and how scaling and distribution work under these limits.
Security	L78-L89	Encrypting VMSS disks (CLI, PowerShell, ARM), configuring Azure Disk Encryption with Key Vault and extensions, and securing scale sets via Azure Policy and RBAC for standby pools.
Configuration	L90-L133	Configuring VM Scale Sets: templates, networking, disks, images, zones, upgrades, autoscale, repairs, standby pools, instance mix/protection, maintenance, and CLI/PowerShell/API management.
Integrations & Coding Patterns	L134-L139	Configuring VM scale set standby pools with Log Analytics for monitoring and integrating scale sets with Azure DSC extension for automated configuration management.
Deployment	L140-L146	Creating VM scale sets from generalized/specialized Shared Image Gallery images, migrating flexible sets to zonal, and deploying apps onto scale set instances.

Troubleshooting

Topic	URL
FAQ and troubleshooting for VM scale set instance mix	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-mix-faq-troubleshooting
FAQ and troubleshooting for VM scale set standby pools	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-faq
Troubleshoot autoscale issues in Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-troubleshoot

Best Practices

Topic	URL
Configure rolling upgrades for production scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-configure-rolling-upgrades
Use MaxSurge rolling upgrades to improve uptime	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-maxsurge

Decision Making

Topic	URL
Apply Azure Hybrid Benefit to Linux scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/azure-hybrid-benefit-linux
Migrate workloads to Flexible orchestration scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/flexible-virtual-machine-scale-sets-migration-resources
Decide when to use instance mix in VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-mix-overview
Compare Uniform and Flexible VMSS APIs	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/orchestration-modes-api-comparison
Use Spot Placement Score to plan deployments	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/spot-placement-score
Balance Spot and standard VMs with Priority Mix	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/spot-priority-mix
Use standby pools to reduce VM scale set latency	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-overview
Use Spot VMs in scale sets for cost savings	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/use-spot
Select autoscale options for Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-autoscale-overview
Design and choose features for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-design-overview
Choose and configure fault domains for scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-manage-fault-domains
Choose VM scale set orchestration mode in Azure	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-orchestration-modes
Choose upgrade policy modes for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-upgrade-policy

Architecture & Design Patterns

Topic	URL
Use proximity placement groups with scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/proximity-placement-groups

Limits & Quotas

Topic	URL
Azure VM Scale Sets FAQs on limits and behavior	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-faq
Understand placement groups and scale set capacity limits	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-placement-groups

Security

Topic	URL
Create and encrypt VM Scale Sets via ARM	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-azure-resource-manager
Encrypt VM Scale Set disks with Azure CLI	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-cli
Sequence extensions for VMSS disk encryption	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-extension-sequencing
Configure Key Vault for VMSS disk encryption	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-key-vault
Enable Azure Disk Encryption for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-overview
Encrypt VM Scale Set disks with PowerShell	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/disk-encryption-powershell
Apply built-in Azure Policy to VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/policy-reference
Configure RBAC permissions for VM scale set standby pools	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-configure-permissions

Configuration

Topic	URL
Alert on Automatic Instance Repairs ServiceState changes	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/alert-rules-automatic-repairs-service-state
Enable Automatic Zone Balance on scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/auto-zone-balance-enable
Use Automatic Zone Balance for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/auto-zone-balance-overview
Define VM scale set configuration with ARM templates	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/flexible-virtual-machine-scale-sets-rest-api
Configure instance mix for Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-mix-create
Update instance mix settings on Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-mix-update
Inspect instance mix configuration on VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-mix-view
Enable resilient create and delete for scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/resilient-vm-create-delete
Create and configure standby pools for VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-create
Retrieve standby pool and instance details for VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-get-details
Understand and query standby pool health state in VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-health-state
Get prediction results to size VM scale set standby pools	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-prediction-results
Configure Spot instances in VM scale set standby pools	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-spot-instances
Update or delete standby pools for Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-update-delete
Configure attached data disks for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-attached-disks
Configure automatic instance repairs for scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-instance-repairs
Configure automatic OS image upgrades for VMSS	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-upgrade
Change upgrade policy mode on existing scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-change-upgrade-policy
Sequence VM extensions in Azure scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-extension-sequencing
Configure Application Health extension for scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-health-extension
Understand and use instance IDs in scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-instance-ids
Configure instance protection on VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-instance-protection
Handle maintenance notifications for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-maintenance-notifications
Manage VM Scale Sets using Azure CLI commands	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-manage-cli
Manage VM Scale Sets with Azure PowerShell	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-manage-powershell
Reference custom images in scale set templates	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-mvss-custom-image
Use existing virtual networks in VMSS templates	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-mvss-existing-vnet
Configure guest-metric autoscale for Linux VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-mvss-guest-based-autoscale-linux
Author basic ARM templates for VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-mvss-start
Configure networking for Azure VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-networking
Perform manual instance upgrades in VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-perform-manual-upgrades
Reimage virtual machines in a scale set	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-reimage-virtual-machine
Configure custom metrics for rolling upgrades	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-rolling-upgrade-custom-metrics
Configure scale-in policies for Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-scale-in-policy
Define scaling profiles for Azure VM scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-scaling-profile
Set upgrade policy mode on VM Scale Sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-set-upgrade-policy
Enable terminate notifications for scale set instances	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-terminate-notification
Modify VM Scale Set model and configuration via APIs	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-upgrade-scale-set
Configure VM Scale Sets with availability zones	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-use-availability-zones
Configure and manage zone balancing in scale sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-zone-balancing

Integrations & Coding Patterns

Topic	URL
Integrate VM scale set standby pools with Azure Log Analytics	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/standby-pools-monitor-pool-events
Integrate VM Scale Sets with Azure DSC extension	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-dsc

Deployment

Topic	URL
Create scale sets from generalized gallery images	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-generalized-image-version
Create scale sets from specialized gallery images	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/instance-specialized-image-version
Migrate regional flexible scale sets to zonal sets	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/migrate-scale-set-flex-to-availability-zones
Deploy applications to VM Scale Set instances	https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-deploy-app