Add SMB share pre-flight validation to AVD deployment (storage-agnostic)

[kristopherjturner]

Problem

The AVD deployment validation matrix (docs/guides/validation-matrix.md) checks FSLogix mounting as a post-deployment step, but it does not validate that the SMB share is actually accessible before session hosts attempt to mount profiles. This leads to silent FSLogix failures at user logon.

Regardless of what storage solution the customer uses for profile SMB shares (SOFS, Azure Files, NAS, Cloud Cache), the pre-flight validation should be the same:

Proposed SMB Share Pre-Flight Checks

Check	What It Validates	How
SMB Connectivity	Session host subnet can reach the share on port 445	Test-NetConnection -Port 445
Share Access	Machine account or user can enumerate the share	Get-SmbShareAccess / net use
NTFS Permissions	CREATOR OWNER + Domain Users ACL model present	Get-Acl on share root
Share Settings	Continuously Available (for SOFS), CachingMode=None	Get-SmbShare properties
DNS Resolution	Share FQDN resolves correctly	Resolve-DnsName
FSLogix Path Format	Share path matches expected format (\\server\share)	Regex validation
Capacity	Sufficient free space for expected user count	Get-PSDrive / WMI query

Key Point

This validation should be storage-solution agnostic. Whether the customer deployed SOFS, Azure Files, or any other SMB share, these checks should work the same way.

Acceptance Criteria

• Add SMB share pre-flight validation to AVD deployment validation
• Implement as a PowerShell script (e.g., Test-ProfileShareReadiness.ps1)
• Include in the validation matrix documentation
• Test against SOFS, Azure Files, and generic SMB shares
• Add to CI/CD pipeline as a pre-deployment gate
• Document required share configuration for any SMB share (not just SOFS)

Affected Repos

• azurelocal-avd — validation scripts, docs/guides/validation-matrix.md