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Show-AzVMQuotaReport.ps1

Single-threaded Azure VM quota reporting script that provides streamlined quota analysis for smaller deployments or learning scenarios.

Overview

This PowerShell script offers a simplified approach to Azure VM quota analysis. Unlike its multi-threaded counterpart, it processes subscriptions sequentially and displays results in a formatted table, making it ideal for smaller estates or when you're learning how Azure quota management works.

Key capabilities

  • Sequential processing: Straightforward single-threaded execution for easier debugging
  • Formatted output: Displays results in a clean table format at completion
  • Zone restriction detection: Identifies which availability zones are restricted for specific VM SKUs
  • Physical zone mapping: Optional mapping of logical to physical zones for cross-subscription planning
  • Educational design: Simpler code structure for understanding quota analysis patterns

When to use this script

  • Learning Azure quota management concepts
  • Analyzing smaller subscription counts (< 10 subscriptions)
  • Debugging quota issues with verbose output
  • Quick ad-hoc quota checks for specific SKUs/regions
  • Teaching quota analysis patterns to new team members

Comparison with Get-AzVMQuotaUsage.ps1

Feature Show-AzVMQuotaReport Get-AzVMQuotaUsage
Threading Single-threaded Multi-threaded (configurable)
Best for < 10 subscriptions 100+ subscriptions
Performance Sequential Parallel processing
Code complexity Simpler Production-optimized
Output format Table + CSV CSV only
Use case Learning/debugging Production analysis

Prerequisites

# Install Azure PowerShell module
Install-Module -Name Az -Repository PSGallery -Force

# Authenticate to Azure
Connect-AzAccount

# Verify subscription access
Get-AzSubscription | Select-Object Name, Id, State

# Check Reader permissions
Get-AzRoleAssignment | Where-Object {$_.RoleDefinitionName -like "*Reader*"}

Parameters

Parameter Type Description Default
SKUs String[] Array of VM SKU names to analyze Catalogs API-first discovery; falls back to deprecated CSV only if API lookup fails and -SKUs is omitted
Locations String[] Array of Azure regions to query All regions
SubscriptionIds String[] Array of subscription IDs to analyze All accessible subscriptions
CatalogLocation String Azure region used for Catalogs API lookup eastus
OutputFile String CSV output filename QuotaQuery.csv
UsePhysicalZones Switch Map logical zones to physical datacenters False
MeterDataUri String Deprecated fallback source URI for VM SKU metadata, used only when Catalogs API lookup fails and -SKUs is not provided Azure public data

Usage examples

Basic quota check for specific SKUs

.\Show-AzVMQuotaReport.ps1 -SKUs @('Standard_D2s_v5', 'Standard_E4s_v5') -Locations @('eastus', 'westus2')

Analyze specific subscriptions with physical zone mapping

.\Show-AzVMQuotaReport.ps1 `
    -SubscriptionIds @('sub1-guid', 'sub2-guid') `
    -UsePhysicalZones `
    -OutputFile "DevSubscriptionQuota.csv"

Quick quota audit for a single region

.\Show-AzVMQuotaReport.ps1 `
    -SKUs @('Standard_D4s_v5') `
    -Locations @('eastus') `
    -OutputFile "EastUSQuotaCheck_$(Get-Date -Format 'yyyyMMdd').csv"

Full analysis with default SKU discovery

.\Show-AzVMQuotaReport.ps1 -OutputFile "CompleteQuotaAnalysis.csv"

Sample output

Running the script produces both console output and a CSV file:

Console output

Querying Azure Catalogs API for VM SKU details in eastus
Retrieved 412 unique VM SKUs from Catalogs API
Listing Subscriptions
Processing subscription: Development (12345678-abcd-1234-5678-123456789012)
  Analyzing location: eastus
    Checking SKU: Standard_D2s_v5
    Checking SKU: Standard_E4s_v5
  Analyzing location: westus2
    Checking SKU: Standard_D2s_v5
    Checking SKU: Standard_E4s_v5

Results saved to: QuotaQuery.csv

Summary Table:
Subscription    Location    SKU                 CoresUsed/Total    Zones Available
------------    --------    ---------------     ---------------    ---------------
Development     eastus      Standard_D2s_v5     8/100             1,2,3
Development     eastus      Standard_E4s_v5     0/100             1,2,3
Development     westus2     Standard_D2s_v5     4/100             1,2,3
Development     westus2     Standard_E4s_v5     16/100            1,2,3

CSV output

TenantId,SubscriptionId,SubscriptionName,Location,Family,Size,RegionRestricted,ZonesPresent,ZonesRestricted,CoresUsed,CoresTotal
12345678-1234-1234-1234-123456789012,abcd1234-5678-90ab-cdef-123456789012,Development,eastus,standardDSv5Family,Standard_D2s_v5,False,"1,2,3",,8,100
12345678-1234-1234-1234-123456789012,abcd1234-5678-90ab-cdef-123456789012,Development,eastus,standardESv5Family,Standard_E4s_v5,False,"1,2,3",,0,100
12345678-1234-1234-1234-123456789012,abcd1234-5678-90ab-cdef-123456789012,Development,westus2,standardDSv5Family,Standard_D2s_v5,False,"1,2,3",,4,100
12345678-1234-1234-1234-123456789012,abcd1234-5678-90ab-cdef-123456789012,Development,westus2,standardESv5Family,Standard_E4s_v5,False,"1,2,3",,16,100

Understanding the output

  • TenantId: Microsoft Entra tenant identifier
  • SubscriptionId: Unique subscription identifier
  • SubscriptionName: Friendly subscription name
  • Location: Azure region
  • Family: VM family for quota calculation
  • Size: Specific VM SKU
  • RegionRestricted: Whether the SKU has regional restrictions
  • ZonesPresent: Available availability zones
  • ZonesRestricted: Zones requiring enablement request
  • CoresUsed: Current vCPU consumption
  • CoresTotal: Total vCPU quota limit

Troubleshooting

Script runs slowly

This is expected behavior for the single-threaded version. For faster processing:

# Use the multi-threaded version instead
.\Get-AzVMQuotaUsage.ps1 -Threads 4

Catalogs API returns no SKU data

The script now uses the Catalogs API as the primary SKU source. If SKU discovery fails:

# Verify the selected catalog location
Get-AzLocation | Where-Object Location -eq 'eastus'

# Verify the Catalogs API permission is available
Get-AzRoleAssignment |
    Where-Object { $_.RoleDefinitionName -like '*Reader*' }

If you already know the SKU names, pass them with -SKUs to skip catalog discovery.

Authentication or permission errors

Catalog lookup requires an authenticated Az session and the Microsoft.Capacity/catalogs/read permission in addition to subscription read access.

# Clear and re-authenticate
Clear-AzContext -Force
Connect-AzAccount -Tenant 'your-tenant-id'

# Verify current context
Get-AzContext | Select-Object Account, Subscription, Tenant

If the script reports an authorization failure from the Catalogs API, ask your Azure administrator to grant access that includes Microsoft.Capacity/catalogs/read.

CSV fallback behavior

If the Catalogs API lookup fails and you do not pass -SKUs, the script falls back to the deprecated meter data CSV source. That fallback helps older workflows continue, but it may not include the latest SKU catalog changes.

# Check whether the default local fallback CSV exists after a failed Catalogs API lookup
Test-Path "AutofitComboMeterData.csv"

Empty zones data

# Some regions don't support availability zones
Get-AzLocation | Where-Object Location -eq 'westus' |
    Select-Object -ExpandProperty Zones

# If empty, the region doesn't support zones

Educational value

This script serves as a learning tool for understanding:

  • How Azure organizes quota by VM family
  • The relationship between logical and physical zones
  • Sequential API interaction patterns
  • CSV export for further analysis

For production use with large subscription counts, use Get-AzVMQuotaUsage.ps1 which provides:

  • Parallel processing for 10x faster execution
  • Configurable thread counts
  • Better error handling for large-scale analysis

Performance comparison

Subscriptions Show-AzVMQuotaReport Get-AzVMQuotaUsage (4 threads)
5 ~2 minutes ~30 seconds
25 ~10 minutes ~3 minutes
100 ~40 minutes ~10 minutes

Script source

View full script source →

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