Key takeaways
- Act fast: The longer you wait, the lower your recovery chances
- Never write new data to a drive where you lost a VM, as it can permanently overwrite recoverable data
- Physical drive failure (clicking sounds, smoke, not detected) requires professional cleanroom recovery
- Complex RAID/VMFS failures need expert intervention to prevent permanent data loss
Virtualization has changed the way businesses manage IT, but it hasn't eliminated data loss. In fact, it has added a layer of complexity. When a physical server fails, you lose one machine. When a VMware datastore fails, you could lose dozens of servers instantly.
VMware is a virtual platform provider that allows users to test new applications in different systems and formats. From getting the VMware Disk File Not Found message to other data loss scenarios, there are four proven methods to restore VMware files that we’ll break down in this article.
Important: If you are facing a corrupted datastore, a deleted VMDK file, or a RAID failure, stop using it immediately. Continued use of the storage device can permanently overwrite the data you are trying to save.
What is VMware data recovery?
VMware data recovery refers to the process of restoring lost, corrupted, or inaccessible data from Virtual Machines (VMs) or VMware File Systems (VMFS). This includes:
- Recovering accidentally deleted files
- Restoring corrupted .vmdk (Virtual Machine Disk) files
- Rebuilding failed RAID arrays hosting virtual environments
- Repairing VMFS corruption from power outages or hardware failures
The "Golden Rule" of virtual recovery
Before attempting any of the steps below, you must understand the risk. If your data loss is due to physical hardware failure (clicking sounds from drives, smoke, or water damage), software cannot help you. It will make things worse. In these cases, contact SalvageData’s Emergency Recovery Services immediately.
Quick decision guide: Which recovery method do you need?
Solution 1. VMware native recovery tools
Best for: Accidental deletions, recent configuration errors, and snapshot issues.
Skill Level: Beginner/Intermediate
Before looking for third-party tools, check whether VMware’s native features can help you retrieve your files.
1. Check for snapshots
A VMware snapshot is a "point-in-time" copy of a virtual machine's disk file (VMDK) that preserves its state and data configuration by freezing the original disk and recording all subsequent changes in a separate "delta" file.
While essential for quickly reverting errors after system updates, snapshots are not automatic by default. You must manually trigger it, or explicitly configure it to run automatically using vCenter schedules or third-party backup software.
If a VM was corrupted after an update or a specific change, reverting to a previous snapshot is the fastest solution.
- Log in to vSphere Client.
- Right-click the problematic Virtual Machine.
- Select Snapshots > Manage Snapshots.
- Select a restore point created before the data loss, then click Revert.
Limitation: If the VM was completely deleted (not just corrupted), snapshots won't help.
2. Recover from backups (Veeam, Nakivo, etc.)
If the VM is deleted entirely, snapshots won't help. You need your external backups. Most enterprise environments run nightly backups.
- Locate your backup repository.
- Initiate a "Full VM Restore" to a strictly new location (do not overwrite the original location, just in case).
Don't have a backup strategy? Review our VMware backup solutions comparison and learn about proper server backup procedures to prevent future disasters. For complex environments, consider implementing a multi-cloud backup strategy.
Solution 2. Software recovery
Best for: Deleted files inside the VM, formatted VMFS volumes, minor logical corruption.
Skill Level: Intermediate
If native tools fail, you may need third-party data recovery software. These tools scan the VMFS volume to find "ghost" files.
How it works:
- Stop writing to the drive.
- Install the recovery software on a different machine (never install it on the drive you are recovering from).
- Connect the VMware datastore (LUN) to the recovery machine.
- Scan for .vmdk files.
Limitations of software recovery
- Time-consuming: Large volumes can take days to scan
- Low success with severe corruption: Cannot repair physical damage or complex RAID failures
- Risk of incomplete recovery: Free tools often cannot reconstruct large, fragmented VMDK files
- No physical repair capability: Zero success rate with clicking drives or failed controllers
For critical business data, software-only recovery adds risk. Professional services verify and guarantee data integrity.
Solution 3. Command line recovery
Best for: Corrupt VMDK descriptor files, VMFS file locking issues.
Skill Level: Advanced IT Professional
Sometimes the data is there, but ESXi cannot read the descriptor file. You can often fix this using the command line interface (CLI).
A VMDK consists of two parts: the "flat" file (data) and the descriptor file (text).
The Descriptor File (.vmdk) is a tiny text file that acts as the "Instruction Manual." It contains metadata and settings (such as cylinder, head, and sector information) that tell VMware exactly how to read the virtual hard drive.
The Flat File (-flat.vmdk) is the "Actual Content." It is a massive binary file that stores the raw data for your operating system, applications, and documents. Without the descriptor file to explain the layout, the system sees this merely as a meaningless pile of data.
If the descriptor is deleted, the VM won't boot, but your data is safe.
- Enable SSH on your ESXi host and log in via PuTTY.
- Navigate to the VM directory: cd /vmfs/volumes/YOUR_DATASTORE/YOUR_VM_FOLDER
- Identify the size of the flat file: ls -l *-flat.vmdk
- Use vmkfstools to create a new temp disk (which generates a new descriptor): vmkfstools -c [SIZE]G -a lsilogic temp.vmdk
- Edit the new descriptor to point to your original flat file
- Rename and test the reconstructed VMDK
Critical Warning: One wrong command can permanently delete your flat file. If you're uncomfortable with Linux command lines, skip this method and contact professionals.
For other common ESXi issues, see our VMware troubleshooting guide.
Solution 4. Professional VMware data recovery services
Best for: RAID failures, Physical HDD/SSD failure, Ransomware, Critical Business Data.
Skill Level: Expert (Outsourced)
When software fails or hardware is physically damaged, you need professional service. VMware environments often live on RAID arrays (RAID 5, RAID 6, RAID 10). If multiple drives fail, the array collapses, taking all VMs with it.
How SalvageData recovers VMware environments
Unlike software-only approaches, we work on physical and logical levels simultaneously:
1. Hardware repair (ISO-5 Cleanroom)
We repair or replace failed drive components in a certified cleanroom environment, preventing further contamination.
2. RAID reconstruction (Controller-Independent)
We virtually rebuild RAID parameters without needing the original controller. Our engineers reverse-engineer stripe size, offset, and rotation to reconstruct the array.
3. VMFS extraction (Manual Parsing)
We manually parse the VMFS file system to extract .vmdk, .vmx, and .nvram files, even from severely corrupted volumes.
4. Verification (Before Delivery)
We test recovered VMs to ensure they boot properly before returning your data.
Why choose professional recovery?
- No data, no charge guarantee on most recoveries
- 24/7 emergency service for business continuity
- Secure chain of custody with SOC 2 compliance
- Free evaluation and quote within hours
Common VMware data loss scenarios
To understand how to fix it, it helps to know what went wrong.
VMFS corruption
What happened: VMFS is a clustered file system. Power outages, aborted snapshot commits, or storage controller failures can corrupt metadata, making the entire volume unreadable.
Best recovery approach: Software for minor corruption, professional for severe cases.
Deleted VMDK files
What happened: Human error is a leading cause of data loss. Removing a VM from inventory is safe, but selecting "Delete from Disk" permanently wipes files.
Best recovery approach: Backups, if available. Otherwise, the software, if caught quickly.
RAID Controller failure
What happened: The hardware card managing your drives failed. The ESXi host loses connection to storage.
Critical: Do NOT initialize or "re-stripe" the array, as this destroys data patterns permanently.
Best recovery approach: Professional data recovery. RAID failures require specialized equipment and expertise.
Snapshot consolidation failure
What happened: VMware failed to merge snapshot delta files back into the base disk, leaving the VM in an inconsistent state.
Best recovery approach: Native tools or command line to manually consolidate snapshots.
FAQ: VMware data recovery
How to avoid VMware data loss?
The best recovery is prevention. Implement these practices:
- Automated backups: Schedule daily backups to external storage using proven VMware backup solutions
- Regular snapshots: Create snapshots before major updates or changes
- RAID monitoring: Use active monitoring tools to detect drive degradation before failure.
- Update management: Test updates in non-production environments before deploying to production.
- Disaster recovery planning: Document your server backup procedures and regularly test restorations.
Can I recover a deleted virtual machine without a backup?
Yes, but it is difficult.
When a VM is deleted, the file system marks the space as "available." If you act quickly before new data is written to that space, recovery software or professional services can carve the raw data to rebuild the VMDK.
What is the difference between VMFS and NTFS recovery?
VMFS is a proprietary file system developed by VMware. Standard Windows recovery tools (designed for NTFS) cannot read VMFS volumes. You need specialized tools or services that understand the VMFS structure.
How long does professional VMware recovery take?
It depends on the damage. Logical issues (such as deleted files) can often be resolved remotely within 24-48 hours. Physical RAID failures requiring cleanroom work may take 3-7 days.
Can I use free tools to recover my VM?
Free tools are good for diagnostics (checking whether files are present), but they often cannot reconstruct large, fragmented VMDK files. For critical business data, relying on free tools adds a risk of incomplete recovery.
What are Guest OS and Host OS?
The virtual machine and the guest operating systems (OS) are accessed from the host system.
Guest OS is the system installed through the virtual machine into the host system. Meanwhile, the host OS is on your computer's hard disk; it’s the primary operating system of the computer.
The host OS provides other systems with services like web, printer, and database access.
How to recover data from a guest OS?
You can use the same methods described in this guide to restore lost data from the guest OS. Only install the recovery software in the guest OS so the program can find the files there.
What are the benefits of using a virtual machine?
Virtual machines offer a lot of conveniences, such as:
- Easy maintenance
- Provide high security
- Convenient recovery
- Support for multiple operating systems