VMware ESXi Data Recovery
Direct answer
VMware ESXi and vSphere are standard in corporate virtualized environments, but fail from corrupted VMFS, inaccessible datastores after RAID failure, stuck snapshots, accidental VM deletion and bad version updates. HD Doctor recovers 92% of VMware cases with individual VMDK extraction, VMFS rebuild and disk image validation. With 24+ years and 880+ ESXi environments solved.
Critical: do NOT run esxcli storage vmfs recover, do NOT force mount datastore with I/O errors, do NOT delete orphan VMDKs without cloning. In vSphere, wrong intervention can propagate corruption via DRS/HA to other hosts.
How VMware ESXi and VMFS work
ESXi is VMware's type-1 hypervisor with proprietary VMFS file system (versions 3/5/6), optimized for multi-host concurrency in vSAN/SAN. VMs are stored as VMDK (virtual disk), VMX (config), VSWP (swap) and snapshots as delta files. Common failures include VMFS metadata heartbeat corruption, datastores stuck by SAN multipath and orphaned VMs after DRS failures.
Common VMware ESXi symptoms
- Datastore shows "Inaccessible" status in vSphere
- VMs appear as "Invalid" or "Orphaned"
- Snapshot consolidation fails with "insufficient space"
- VMFS metadata corruption in /var/log/vmkernel.log
- ESXi host can't mount the datastore
- vmdk reported as zero bytes or corrupted
- VMs don't boot after snapshot revert
- vSAN with persistent "reduced redundancy"
Most frequent VMware ESXi causes
| Cause | % | Recoverable? |
|---|---|---|
| RAID/SAN failure under datastore | 30% | ✅ Yes, RAID rebuild + VMFS read |
| VMFS metadata heartbeat corruption | 20% | ✅ Yes, heartbeat repair |
| Broken snapshot tree (orphan delta) | 15% | ✅ Yes, chain rebuild |
| Accidental VMDK or VM deletion | 12% | ✅ Yes, specific file carving |
| Bad ESXi update | 10% | ✅ Yes, data separate from hypervisor |
| vSAN with host failure (inaccessible object) | 8% | ✅ Yes, vSAN object rebuild |
| Other (stuck storage vMotion, BSY) | 5% | ✅ Yes |
Source: HD Doctor internal stats on 880 VMware ESXi cases between 2022 and 2025.
What NOT to do with a failing VMware ESXi
- 1.Do not run esxcli storage vmfs recover without backup. Can rewrite metadata over recoverable data.
- 2.Do not force snapshot consolidation with broken chain. On inconsistent chain, consolidation writes over delta files we need.
- 3.Do not delete VMs marked as "Invalid". VMware marks as invalid for read failure, not lost data.
- 4.Do not run vSAN object repair on degraded pool. Can propagate corruption between hosts.
- 5.Do not force mount datastore with I/O errors. Each attempt stresses the underlying RAID/SAN.
- 6.Do not swap hardware without config dump. Different HBAs and controllers may have different mapping.
How HD Doctor recovers VMware ESXi
We work on bit-by-bit clones of datastore LUNs/drives. VMFS is virtually rebuilt and each VMDK extracted and individually validated.
- 1
Storage/RAID drive intake
For SAN, we receive LUNs in specific adapter. For DAS, the array drives.
- 2
Diagnosis within 24h
Drive analysis + VMFS metadata technical read to identify corruption type.
- 3
Free written quote with scope
Detailed technical analysis before approval, listing viable VMs.
- 4
Bit-by-bit datastore cloning
PC-3000 with custom retry policy.
- 5
Physical repair if needed
Cleanroom for mechanical cases.
- 6
Virtual VMFS rebuild
Professional software remounts VMFS from clones, with heartbeat and tree repair.
- 7
Individual VMDK extraction and validation
For each VM, we extract VMDKs and validate boot via converter or inspect.
- 8
Snapshot chain rebuild
When there are orphan snapshots, we manually rebuild the chain to present VM in pre-corruption state.
- 9
Delivery + final report
VMDKs on new media with checksum, technical report valid for forensics and corporate insurance.
Turnaround and SLA
| Scenario | Turnaround |
|---|---|
| Corrupted VMFS (1 datastore) | 7–12 business days |
| Datastore with failed RAID | 10–18 business days |
| Broken snapshot chain | 5–10 business days |
| vSAN with host failure | 15–25 business days |
| Corporate emergency SLA | Immediate contact |
- 24h emergency SLA available for data centers and critical vSphere environments.
- No Data, No Charge policy: if we can't recover the critical files you flagged, you don't pay for the service. Diagnosis is free in 92% of cases.
Versions and environments supported
We service VMFS-3, VMFS-5, VMFS-6, vSAN ESA, vSAN OSA. ESXi 5.x, 6.x, 6.5, 6.7, 7.x, 8.x. vSphere Standard, Enterprise Plus. Virtual disk types: thin-provisioned, thick lazy zero, thick eager zero, EZT. Snapshots in SEsparse, vmfsSparse. We support NFS datastores, iSCSI, FC SAN, NVMe-oF and vSAN.
Why HD Doctor for VMware ESXi
- 🏛️24+ years focused exclusively on data recovery
- 🔬Class 100 cleanroom + in-house SAN/NAS infrastructure
- 🧠Virtual VMFS rebuild + individual VMDK extraction
- ⚡24h emergency SLA for corporate data centers
- 🤝Only Western Digital Platinum Partner with a regional lab
- ⚖️Signed engineer report valid for forensics and insurance
VMware ESXi FAQ
VMFS datastore marked inaccessible, recoverable?
Yes, in 90% of cases. Inaccessible in VMFS is usually metadata heartbeat corruption. We repair via virtual rebuild in lab.
Lost VMs after RAID failure. Any chance?
Yes, in 92% of cases. We first rebuild the RAID, then VMFS, then extract individual VMDKs.
Snapshot consolidation failed, VM won't boot. Recoverable?
Yes. On broken snapshot chain, we manually rebuild deltas to present the VM in consistent state.
vSAN with inaccessible object and zeroed data. Can you?
Yes, in 88% of cases. vSAN distributes objects across hosts. We recover via witness analysis and object rebuild.
Do you serve corporate environments with emergency SLA?
Yes. For critical data centers and vSphere, 24h emergency SLA with lab priority and post-recovery support for VM validation.
How does the quote work?
Diagnosis is free. After technical assessment within 24h we send a detailed quote.