HVDRS

Author(s)

• Jason Huebel

Tags

Hyper-V HyperV DRS FailoverCluster LoadBalancing VirtualMachine VM LiveMigration StorageMigration CSV ClusterSharedVolume Affinity WindowsServer Automation

Functions

Invoke-HvDRS Get-HvDRSCluster Enable-HvDRSMaintenance Disable-HvDRSMaintenance Get-HvDRSMaintenanceStatus Enter-HvDRSNodeMaintenance Exit-HvDRSNodeMaintenance Get-HvDRSNodeMaintenanceStatus Add-HvDRSAffinityRule Get-HvDRSAffinityRule Remove-HvDRSAffinityRule Set-HvDRSAffinityRule Test-HvDRSAffinityCompliance Test-HvDRSStorageAffinityCompliance Add-HvDRSGroup Get-HvDRSGroup Remove-HvDRSGroup Set-HvDRSGroup Set-HvDRSVMAutomationLevel Get-HvDRSVMAutomationLevel Remove-HvDRSVMAutomationLevel Get-HvDRSCapacityForecast Invoke-HvStorageDRS

Dependencies

This module has no dependencies.

Release Notes

## 1.6.1
- Fixed latent bugs, of the same class fixed in 1.5.1, that only surfaced under
 Set-StrictMode (which the publish pipeline enables) and were caught while
 preparing this release:
 - Invoke-HvStorageDRS and Test-HvDRSStorageAffinityCompliance both piped
   Get-AffinityRuleSet's output directly into Where-Object to filter storage
   rule types. When no rules are configured at all, this threw under strict
   mode — PowerShell enumerates the ",@()" empty-result wrapper as a single
   pipeline item when piped directly (rather than assigned to a variable
   first), so the Where-Object script block's $_.Type access failed. Both
   call sites now capture into a variable before filtering.
 - Get-HvDRSVMAutomationLevel's no-"-VMName" branch returned an empty result
   without the leading-comma protection Get-AffinityRuleSet and similar
   loaders use, so it collapsed to $null (and threw on .Count) when no
   overrides were configured for a cluster.
 - Get-HvDRSCapacityForecast's -RemoveNode path could return $null for
   VMPlacements/NodeImpact instead of an empty array when a node has no VMs
   or a cluster has only one remaining node.
 No production behavior changes for callers who already handled populated
 results correctly — these only affected the zero-result / no-rules-configured
 edge cases under strict-mode callers.

## 1.6.0
- Added -TrendWindow / -HistoryPath to Invoke-HvDRS: optional rolling-average
 smoothing of node CPU/network utilization and VM CPU/memory-pressure across
 consecutive passes, so a single transient spike doesn't trigger a migration.
 Disabled by default (-TrendWindow 1) — zero behavior change unless opted in.
- Added Enter-HvDRSNodeMaintenance / Exit-HvDRSNodeMaintenance /
 Get-HvDRSNodeMaintenanceStatus: happiness-aware node evacuation (a Hyper-V
 analog of vSphere's "Enter Maintenance Mode") that live-migrates every VM off
 a node using the same Network-Aware/memory-reserve/affinity-rule destination
 selection as Invoke-HvDRS, then pauses the node — or refuses to pause it if
 any VM couldn't be placed.
- Added VM/Host/CSV Groups (Add/Get/Remove/Set-HvDRSGroup) and new
 -VMGroups/-HostGroups/-CSVGroups parameters on Add/Set-HvDRSAffinityRule:
 reusable named groups that affinity rules can reference instead of listing
 members directly. Group membership resolves dynamically at rule-load time —
 editing a group takes effect immediately, with no rule re-save needed.
- Added per-VM automation-level overrides (Set/Get/Remove-HvDRSVMAutomationLevel):
 pin specific VMs to Manual so Invoke-HvDRS/Invoke-HvStorageDRS keep scoring
 and recommending them but never execute a migration/move for them.
- Added Get-HvDRSCapacityForecast: read-only what-if capacity analysis —
 simulate draining a node (-RemoveNode) to check whether every VM on it has a
 valid destination, or simulate adding a hypothetical node (-AddNode) to see
 which currently-unhappy VMs it could absorb.
- Added -WebhookUrl / -WriteEventLog to Invoke-HvDRS and Invoke-HvStorageDRS:
 optional JSON webhook POST and/or Windows Application event log entry
 summarizing each pass. A notification failure is logged as a warning and
 never fails an otherwise-successful pass.
- Added -PassThru to Invoke-HvStorageDRS (previously compute-only), and
 extended the optional ProPack VMM PRO Tips integration to cover storage DRS
 recommendations (ConvertTo-HvDrsStorageProTip, Resolve-VmmStorageIdentity,
 Invoke-HvDrsStorageProTipProbe, and a parallel monitor/rule pair in the
 Management Pack) — previously compute-only.
- Fixed a latent bug in Invoke-HvStorageDRS where its Format-Table calls were
 never piped to Out-Host, so capturing its return value (now needed by
 -PassThru) leaked PowerShell formatting objects onto the output stream. Same
 class of bug already fixed for Invoke-HvDRS in 1.5.0.
- Moved all documentation except README.md into a new docs/ folder
 (docs/INSTALL.md, docs/USAGE.md, docs/TESTS.md, docs/PUBLISH.md) and added
 docs/ARCHITECTURE.md, a new technical design reference.

## 1.5.1
- Fixed three latent bugs where a zero-match result collapsed to $null instead
 of an empty array/collection at a function or switch-expression output
 boundary: Find-MigrationCandidates (no migrations recommended),
 Get-HvDRSAffinityRule (no rules match a filter), and an internal switch-to-
 variable assignment in the same function. These were silently tolerated by
 PowerShell's default null.Count convenience behavior but threw under
 Set-StrictMode, which the publish pipeline enables — surfaced while
 preparing this release. No behavior change for non-strict-mode callers.

## 1.5.0
- Added -PassThru to Invoke-HvDRS: emits each migration recommendation as a structured
 object (ClusterName, VMName, VMId, SourceNode, DestinationNode, scores, ComplianceReason)
 in addition to the existing console output, for programmatic consumers. Fully additive
 and backward compatible — omitting the switch preserves prior behavior.
- Fixed internal Format-Table calls leaking formatting objects onto the function's output
 stream when callers capture Invoke-HvDRS's return value; they now render to the console
 only via Out-Host.

## 1.4.0
- Added Get-HvDRSCluster: lightweight, read-only discovery of cluster nodes, VMs, and
 Cluster Shared Volumes, with no performance-counter collection and no migrations proposed

## 1.3.0
- CRITICAL FIX: the module manifest was missing RootModule, so Import-Module HVDRS
 never loaded HVDRS.psm1 and exported zero functions in every prior published
 version. RootModule = 'HVDRS.psm1' is now set and the module works correctly.
- Fixed Get-AffinityRuleSet returning $null instead of an empty array on a fresh
 rules store, which broke adding the very first affinity rule
- Added storage-specific affinity/anti-affinity rules: VmVmCsvAffinity, VmVmCsvAntiAffinity,
 VmCsvAffinity, VmCsvAntiAffinity
- Add-HvDRSAffinityRule / Set-HvDRSAffinityRule accept -CSVs (and -AddCSVs/-RemoveCSVs)
- Invoke-HvStorageDRS now loads storage rules, runs a compliance pass ahead of the
 happiness pass, and applies soft-rule penalties / compliance bonuses to candidate scoring
- Added Test-HvDRSStorageAffinityCompliance for live VM-to-CSV placement auditing

## 1.2.1
- Documentation only: promoted PowerShell Gallery install to the recommended option in INSTALL.md
- Updated README Quick Start to use Install-Module instead of Copy-Item

## 1.2.0
- Added per-cluster scoping for affinity/anti-affinity rules
- Rules stored in shared JSON file are now filtered by ClusterName at load time
- Add-HvDRSAffinityRule, Get-HvDRSAffinityRule, Remove-HvDRSAffinityRule all accept -ClusterName
- Same rule name may now exist independently across different clusters

## 1.1.0
- Added Storage DRS (Invoke-HvStorageDRS): CSV space and latency happiness scoring,
 greedy storage migration planner, Move-VMStorage execution
- Added affinity/anti-affinity rules (VmVmAffinity, VmVmAntiAffinity, VmHostAffinity,
 VmHostAntiAffinity) with hard (enforced) and soft enforcement modes
- Added two-pass migration planner: compliance pass fixes hard violations first,
 happiness pass applies rule impact scoring
- Added Test-HvDRSAffinityCompliance for live placement auditing

## 1.0.0
- Initial release: VM Happiness scoring, compute DRS, Network-Aware destination
 filtering, aggression levels 1–5, maintenance mode