azure-vm-scalesets

What this skill does

# 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](https://github.com/MicrosoftDocs/mcp/blob/main/README.md)

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