For IT administrators, few things are more stressful than realizing a VMDK file has been deleted. A VMDK (VMware Virtual Machine Disk) is the backbone of any virtual machine, storing everything from the operating system to installed applications and critical user data. Losing it can mean service outages, productivity losses, and in the worst cases, permanent data loss.
Unfortunately, accidental deletions happen more often than most expect. Human error during datastore cleanup, misconfigured automation scripts, or even a rushed migration can lead to the disappearance of a vital virtual disk. The good news is that recovery is possible. With the right tools and careful steps, deleted VMDKs can often be restored, minimizing downtime and avoiding costly consequences.
Explaining VMDK Files and Datastores
A VMDK file is essentially the virtual hard drive of a VMware virtual machine. It contains:
- The VM’s operating system.
- Installed software and applications.
- Configuration files.
- User data and workloads.
These files are typically stored on a VMFS (VMware File System) datastore, which is managed by VMware ESXi hosts. The datastore acts as the storage pool for multiple virtual machines, making it central to virtualization environments.
There are also different types of VMDKs:
- Thin provisioned – grows in size as data is written.
- Thick provisioned – pre-allocates full disk space upfront.
- Flat VMDK – raw disk image holding the actual VM data.
Recovering a deleted VMDK is more complicated than restoring a file from a local disk. VMFS uses its own structure, meaning typical file recovery tools often can’t handle the job directly.
Common Scenarios Leading to Deleted VMDKs
VMDKs can disappear in several ways, including:
- Manual deletion – removing a VM or files directly from vSphere/ESXi.
- Datastore corruption or reformatting – leading to loss of all files.
- Migration or snapshot errors – improper consolidation or cleanup can wipe VMDKs.
- Hardware failures – RAID or NAS issues that compromise datastore integrity.
Safety Precautions Before Attempting Recovery
When a VMDK is deleted, quick action is essential because any new write operation may overwrite recoverable data. The first step is to halt all activity on the datastore—stop writes, power down affected VMs, and avoid creating new snapshots or virtual machines.
Next, secure the environment by cloning or backing up the datastore so recovery efforts can be done on a copy, not the original. It’s also wise to document important VM configuration files (.vmx, .vswp, .log), as they may be necessary to successfully rebuild and restore the virtual machine.
Methods to Recover Deleted VMDKs
Using VMware Native Options
- Check the vSphere Client for available snapshots or VM backups.
- Use vSphere Data Protection or third-party backup appliances like Veeam or Nakivo if configured.
- Run vmkfstools to verify or clone disk files if partial data remains.
Manual Recovery from Datastore
- Open the datastore browser to check for orphaned files.
- Look for flat.vmdk or -delta.vmdk files, which may still exist.
- If descriptor files are missing, they can be manually recreated to point to the flat disk.
Third-Party Data Recovery Tools
When native recovery isn’t enough, specialized tools can help:
- DiskInternals VMFS Recovery – scans VMFS volumes and restores deleted VMDKs.
- R-Studio – supports VMware, RAID, and NAS recovery.
- UFS Explorer – useful for corrupted VMFS partitions.
- ddrescue / Clonezilla – for making raw clones before deeper recovery attempts.
Advanced Case: Recovering VMDKs from RAID or NAS
When a datastore resides on RAID or NAS storage, recovery must start with the underlying system. Attempting to restore VMDKs before rebuilding the array risks further corruption and data loss.
The process typically involves recover deleted vmdk from datastore or reconstructing the RAID/NAS first, then mounting the VMFS datastore and scanning for deleted VMDKs. Specialized tools such as DiskInternals, ReclaiMe, or R-Studio are designed to handle RAID rebuilds and provide access to VMFS volumes for recovery.
Step-by-Step Workflow for Successful Recovery
- Identify datastore type (VMFS version, RAID/NAS backend).
- Stop all writes and clone the datastore.
- Attempt recovery with VMware snapshots or backups first.
- If unavailable, use recovery tools to scan VMFS.
- Rebuild VMDK (descriptor + flat file).
- Register the VM back in inventory.
- Test boot and verify file integrity.
Preventing Future Data Loss
The best recovery is prevention. To reduce the risk of future VMDK loss:
- Implement a solid backup strategy (daily/weekly snapshots + offsite backup).
- Use VMware HA (High Availability) and replication for redundancy.
- Monitor datastore health with tools like Host-Tracker or vCenter alarms.
- Train IT staff to handle datastore operations carefully and avoid misclicks.
Wrapping Up
Deleting a VMDK is not the end of the world, but it is a serious problem that requires quick, careful action. By halting datastore writes, using VMware’s built-in recovery methods, and leveraging specialized tools when necessary, you can often recover lost VMDKs and restore business continuity.
The key is to act fast and prepare ahead of time. With regular backups, proper monitoring, and trained personnel, you can prevent costly data loss and keep your VMware environment resilient.