Mount Vmfs 6 Windows Hot -

How to Hot Mount VMFS 6 on Windows: The Ultimate Guide for Sysadmins

Keywords: Mount VMFS 6 Windows hot, Windows VMFS 6 driver, hot-plug VMware datastore, access VMFS 6 without reboot.

Conditions for Safe Read-Write Hot Mount:

  1. No ESXi host is actively using the LUN. You must remove the datastore from vSphere while keeping the SAN LUN presented.
  2. Disable ATS (Atomic Test & Set) – VMware’s locking mechanism. Without this, ESXi will reclaim the lock mid-operation.
  3. Use a tool like UFS Explorer RW – Only UFS Explorer Professional and Runtime’s GetDataBack support writing to VMFS 6.

Method 1: The Free Tool Approach (Recommended)

The most reliable free tool for this specific task is Open VMFS (formerly associated with Veaam, now an open-source project).

Tool: Open VMFS or specific forks like vmfs6-tools wrapped in a UI. However, for Windows users, the easiest interface is often a tool like Veaam File Manager (for older VMFS) or a compiled binary of vmfs-tools.

Current Best Practice for Windows: Because VMFS6 uses a different hashing structure than VMFS5, many older Windows GUI tools (like the old VMFS Driver) fail. mount vmfs 6 windows hot

  1. Mount the Disk:

    • Connect the drive via USB/ enclosure or mount the raw disk image.
    • Ensure Windows Disk Management sees the disk (it will likely show as "Unknown" or "RAW"). Do not format it if Windows prompts you to.

  2. Use Open VMFS (Console/GUI):

    • There are compiled Windows binaries available on GitHub under the vmfs-tools project.
    • Run the tool to explore the partition structure.
    • This allows "hot" access (accessing the filesystem while it is not mounted by the OS) to extract specific VMDKs or configuration files.

Method 3: Using 7-Zip + VMFS Layer (No Driver – User Mode)

Best for: Emergency read of single files, minimal risk. How to Hot Mount VMFS 6 on Windows:

Believe it or not, 7-Zip (versions 22.00 and newer) includes a VMFS parser in user mode – no kernel driver required. This is the only truly reboot-free method.

Performance Benchmarks: Hot vs Cold

| Method | Reboot Required? | Read Speed | Write Support | VMFS 6 Support | |--------|----------------|------------|---------------|----------------| | StarWind V2V | No | 180 MB/s | No | Full | | 7-Zip User Mode | No | 40 MB/s | No | Partial | | vmfs6-tools | Once (test mode) | 200 MB/s | No | Full | | DiskInternals | No | 220 MB/s | Yes (dangerous) | Full | | VMware DiskMount (legacy) | Yes | N/A | No | No (only VMFS5) |

Introduction: The Challenge of VMFS 6 Accessibility

In the world of virtualization, VMware’s Virtual Machine File System (VMFS) is the gold standard for shared datastores. With the release of vSphere 6.5 and later, VMFS 6 became the default file system, offering superior support for large-capacity drives (up to 64 TB) and automatic space reclamation (UNMAP). No ESXi host is actively using the LUN

However, a common pain point for IT professionals and digital forensics experts remains: How do you mount VMFS 6 on Windows while the system is “hot” (i.e., the virtual machines are still running)?

Whether you need to recover a single file without powering down a production VM, perform a forensic analysis, or migrate data from a failed ESXi host, a "hot mount" solution is critical. This article provides a step-by-step guide, compares tools, and explains the risks associated with mounting VMFS 6 on Windows hot.

3. DiskInternals VMFS Recovery (Paid, Read-Only + Recovery)

This tool allows you to mount VMFS 6 on Windows hot and access it like a regular drive letter. It includes a RAID reconstructor and can even mount snapshots.