VMware is one of the most reliable virtualisation platforms, enabling businesses to run multiple virtual machines efficiently on a single server.
Even so, stable environments are not immune to technical issues. Common VMware errors can disrupt workflows, trigger unplanned downtime and, if handled incorrectly, lead to data loss.
From failed snapshots to corrupted virtual disks, these problems can arise for many reasons, including hardware faults, power interruptions and configuration mistakes. Understanding what causes these errors is the first step towards preventing them.
In this guide, we look at the most frequent VMware errors, what they mean and how to respond in a safe, controlled way.
You will also see when it is time to involve specialists such as RAID Recovery Services for reliable VMware data recovery.
Common Causes of VMware Errors
VMware errors can stem from a range of issues within your hardware stack or configuration. Pinpointing the root cause early helps you avoid extended disruption and reduces the risk of data loss.
Hardware malfunctions: Faulty hard drives, failing RAID controllers or insufficient memory can all create instability, leading to frozen hosts, crashed VMs and access problems.
Corrupted virtual disks (VMDK files): If a VMDK file is damaged by an abrupt shutdown or storage failure, the virtual machine may refuse to boot or present as if data has gone missing.
Misconfigured storage or network settings: Incorrect iSCSI, Fibre Channel or NFS configuration can stop VMs from reaching their underlying storage, triggering recurring connectivity and timeout errors.
Software conflicts and updates: Out of date hypervisors, incompatible VMware Tools or incomplete patching cycles can introduce snapshot, driver and compatibility issues immediately after updates.
Power interruptions or improper shutdowns: Unexpected power loss or forced shutdowns can corrupt active sessions and incomplete write operations, resulting in file system damage and unstable VMs.
For related problems involving host or application instability, see our article on Server Crash to understand how hardware and power failures affect wider server environments.
Top VMware Error Messages and What They Mean
Virtual environments can generate a wide range of warning messages that point to issues with configuration, storage or performance. Below are some of the most common VMware errors and what they typically indicate.
“Cannot open the disk ‘.vmdk’ or one of the snapshot disks.”
This message usually appears when the virtual disk is corrupted, missing from the datastore or referenced incorrectly in the VM configuration.“Failed to lock the file.”
The VM is trying to access a file that is already in use. This is often linked to an improper shutdown, a stale lock file or a conflict caused by snapshots or duplicate registrations of the same VM.“The specified virtual disk needs repair.”
This warning points to damaged metadata within the virtual disk, which prevents normal read or write operations and can stop the VM from booting.“VMware Tools not running.”
Indicates that VMware Tools, which handle guest integration, drivers and performance metrics, are not running correctly. This can affect monitoring, graceful shutdowns and overall VM responsiveness.“A general system error occurred: Internal error.”
A broad error that can signal software bugs, driver conflicts, permission issues or a lack of available storage or memory on the host.
Recognising these messages early helps you narrow down the root cause before attempting any repair or recovery. For a more detailed breakdown, see our reference post on VMware Errors for an expanded overview.
How VMware Errors Affect Virtual Machines
VMware errors can cause significant performance and access issues if they are not resolved promptly. A single corrupted file or misconfiguration can disrupt several virtual machines running on the same host server.
Common effects include:
Inaccessible virtual machines: VMs may fail to power on or can crash during boot if the virtual disk or configuration file is damaged.
Data corruption: When disk operations fail, stored data can become unreadable or partially lost.
Snapshot issues: Failed or incomplete snapshots can consume large amounts of storage and slow down the entire environment.
Downtime and productivity loss: System errors can interrupt business operations until affected VMs are repaired or restored.
In environments where multiple users rely on virtual servers, even minor faults can quickly escalate into serious downtime. Dealing with these issues promptly helps prevent long term damage and data loss.
For support in diagnosing similar failures, you can also review Troubleshoot RAID Failure, which explains how to handle complex storage problems safely.
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Troubleshooting Common VMware Issues
When VMware errors occur, fast but controlled action is essential to avoid making the situation worse. While some minor problems can be resolved through routine maintenance, deeper faults often require professional involvement.
Here are a few safe troubleshooting steps you can take:
Inspect physical disks, memory modules and RAID controllers for warning indicators or failures. Replace or reseat suspect components where necessary, following your change control process.
Confirm that your virtual machines can reach the correct datastores and directories. Misconfigured access rights or incorrect paths can block VM access or prevent disks from mounting correctly.
If you have a recent, verified backup, restoring the affected VM can often resolve snapshot or disk corruption issues without introducing additional risk to your data.
Avoid manually editing VMDK or VMX files unless you have the right expertise. Incorrect changes to core VM files can complicate or even prevent successful recovery later.
VMware logs provide detailed messages and error codes that can guide your next steps. Review host and VM logs carefully before attempting any manual repairs.
If the issue continues after these checks, there may be deeper storage or filesystem problems. For an example of how complex incidents are handled, see our Oracle Database Recovery Case to understand how layered data issues can be managed safely.
When to Seek Professional VMware Data Recovery
Some VMware failures are too severe for routine troubleshooting. When virtual disks are heavily corrupted or the datastore is no longer accessible, trying to fix the issue manually can make recovery significantly harder. In these cases, bringing in professional support is essential.
Specialist recovery is often required when VMDK files are damaged after system crashes, storage controllers fail or snapshots are left in an incomplete state. Power interruptions during write operations can also corrupt the wider virtual environment, leaving multiple VMs offline and inaccessible.
At RAID Recovery Services, our engineers carry out VMware data recovery in controlled lab conditions.
We rebuild damaged RAID arrays, repair corrupted virtual disks and restore data from failed or deleted virtual machines. Each recovery is handled with a focus on preserving file integrity and reducing downtime as much as possible.
For more insight into how hardware level repairs are managed, explore RAID Controller Failure Recovery to see how complex system faults are resolved securely.
Preventing Future VMware Errors
Preventing VMware errors requires proactive monitoring and disciplined system maintenance. Regular checks and safe storage practices significantly reduce the risk of corruption or unexpected downtime.
Here are a few ways to keep your VMware environment stable and limit common VMware errors:
Schedule Routine Backups
Always maintain up to date backups of your virtual machines and configuration files. Store them on separate storage systems or in the cloud to add an extra layer of protection.
Monitor Hardware Health
Track the condition and performance of storage drives, RAID controllers and memory modules to detect early warning signs of failure before they affect production workloads.
Keep VMware Software Updated
Regularly update VMware Tools and ESXi versions to avoid compatibility issues, close security gaps and improve stability and performance across your hosts.
Use Reliable Power Protection
Install uninterruptible power supplies to protect against sudden outages. This helps prevent data corruption during unexpected power loss or voltage fluctuations.
Implement Data Loss Prevention Practices
Configure automated alerts for system errors, failed snapshots and storage latency. Build redundancy into critical workloads so that individual host or disk issues do not immediately impact users.
Strong maintenance policies and active monitoring can prevent most VMware problems before they cause serious damage.
For additional guidance, see Data Loss Prevention and Server Cloud Backup to strengthen your long term protection strategy.
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Frequently Asked Questions
What causes most VMware errors?
VMware errors typically arise from hardware faults, corrupted VMDK files or misconfigured storage settings. Power outages, failed updates and incompatible software versions can also trigger serious issues in virtual environments.
How can I fix a corrupted VMDK file?
A corrupted VMDK file should be handled with care. Avoid trying to repair or edit it manually, as this often makes the damage worse. Instead, contact specialists such as RAID Recovery Services to rebuild or restore the virtual disk safely.
Why does my VMware virtual machine fail to start?
A virtual machine may fail to boot if its disk is missing, locked or corrupted. This can also happen when snapshots are incomplete or the storage path is misconfigured. Reviewing the VM and host logs will help pinpoint the exact cause.
Can I recover data from a failed VMware host?
Yes. Data can often be recovered from a failed VMware host using specialist tools and processes. RAID Recovery Services can reconstruct damaged datastores, repair RAID volumes and recover virtual machines that are no longer accessible.
How do I prevent VMware data corruption?
Schedule regular backups, monitor hardware health and avoid abrupt shutdowns. Always apply software updates in a controlled way and use redundant storage systems to minimise the risk of corruption or data loss.