VMware ESXi and vSphere Cluster Management

VMware Player Virtual Machine Files Explained

Learn what VMware Player VM files do, including VMX, NVRAM, VMDK, VMEM, VMSD, VMSN, VMSS, and log files, plus safe backup guidance.

A VMware Player virtual machine (VM) is a software-defined computer that runs a guest operating system on a physical computer. The physical computer's operating system is the host operating system.

On the host, a VM is represented by several related files in a VM directory. The VM's name commonly appears as the base name of those files. For example, an Ubuntu VM may contain Ubuntu.vmx, Ubuntu.nvram, and Ubuntu.vmdk.

Where VMware Player Stores Virtual Machine Files

When you create a VM, VMware Player stores its files in a folder on the host operating system. The folder may be in a default VMware location or in a location you selected during VM creation. Use the host file manager to locate the folder associated with the VM.

A typical folder might look like this:

Ubuntu/
├── Ubuntu.vmx
├── Ubuntu.nvram
├── Ubuntu.vmdk
├── Ubuntu.vmsd
├── Ubuntu.vmsn
├── Ubuntu.vmss
├── Ubuntu.vmem
└── vmware.log

Not every file appears in every VM. Snapshot files generally appear only when snapshots exist, and suspend-related files may appear only while a VM is suspended or while associated state data remains.

Primary VMware Player VM Files

The .vmx configuration file

The .vmx file is the primary VMware virtual machine configuration file. It records the VM's virtual hardware and operational settings, including memory allocation, processor configuration, virtual disks, network adapters, and other devices.

VMware Player uses this file to open and identify the VM. For example, Ubuntu.vmx tells VMware Player how the Ubuntu VM is configured and which virtual disk files it uses.

The .nvram firmware file

The .nvram file stores the VM's virtual BIOS or firmware state. It can contain firmware-level settings, such as the state of virtual firmware configuration.

This is different from the .vmx file. The .vmx describes the virtual hardware and VMware settings, while the .nvram preserves settings belonging to the VM's virtual firmware.

VMware log files

vmware.log and VM-name-based log files record VM activity, warnings, and errors. VMware Player can use these records to help diagnose startup failures, device problems, crashes, and configuration issues.

Logs are diagnostic records. They are not the guest operating system's files and do not contain the VM's virtual hard drive contents. When investigating a problem, inspect the most recent messages in vmware.log or the relevant VM-specific log file.

The .vmem memory or paging file

A .vmem file is associated with the VM's memory or paging state. It relates to the VM's RAM use and may be present depending on the VM's state and configuration.

A .vmem file is not permanent virtual disk storage. The guest operating system, installed applications, and user documents are stored on the virtual disk, normally represented by one or more .vmdk files.

Virtual Disk Files

The .vmdk virtual disk format

A .vmdk file is a VMware virtual disk file. It represents a virtual hard drive available to the guest operating system. Its contents can include the guest operating system, installed software, user data, and other files that would normally be stored on a physical hard drive.

A VM can have more than one virtual disk. For example, one .vmdk might contain the operating system while another stores application or data files. Some virtual disks are represented by more than one disk-related file, so do not assume that a single visible filename contains all disk data.

Snapshot and Suspension Files

The .vmsd snapshot metadata file

The .vmsd file contains snapshot metadata. It records information about snapshots and their relationships. It is metadata, not the complete captured machine state and not the guest's entire disk data.

The .vmsn snapshot state file

The .vmsn file stores snapshot state. When applicable, it can preserve the VM's execution state at the instant a snapshot is taken. Snapshot disk data is handled through the VM's disk files and snapshot-related disk chain.

A snapshot is not the same as an ordinary powered-off VM. A powered-off VM has been shut down without preserving a running execution state. A snapshot records a saved point in the VM's disk state and, when applicable, execution state.

The .vmss suspended-state file

The .vmss file preserves the state needed to resume a suspended VM. Suspension pauses a running VM while retaining its current execution state for later continuation.

Suspension differs from shutdown and snapshot creation:

• Shutdown: The guest operating system closes normally, and the VM is left powered off.
• Suspension: The current running state is saved so the VM can resume from that point.
• Snapshot: A saved point is created for later reversion or comparison; it may also include execution state when captured from a running VM.

VMware Player Virtual Machine File Types

Snapshot, Suspend, and Powered-Off States Compared

Recognizing an Ubuntu VM Folder

An Ubuntu VM folder can contain files like these:

Ubuntu.vmx      primary virtual hardware configuration
Ubuntu.nvram    virtual BIOS or firmware state
Ubuntu.vmdk     virtual hard disk data
Ubuntu.vmsd     snapshot metadata
Ubuntu.vmsn     saved snapshot state
Ubuntu.vmss     suspended execution state
Ubuntu.vmem     memory or paging state
vmware.log      runtime diagnostic log

The exact contents depend on what has happened to the VM. If no snapshots exist, Ubuntu.vmsd and Ubuntu.vmsn may be absent. If the VM is not suspended, Ubuntu.vmss and related memory-state files may also be absent. Log filenames and additional disk files can vary.

Safely Copying, Moving, or Backing Up a VM

1. Shut down the guest operating system normally.
2. Confirm in VMware Player that the VM is fully powered off, not merely suspended or paused.
3. Close VMware Player or otherwise ensure that it is no longer writing to the VM files.
4. Copy the complete VM folder, keeping the configuration, disks, firmware data, snapshots, and state files together.
5. When snapshots are present, include every related snapshot and disk-chain file. Do not selectively copy only the base .vmdk.

Before manually modifying or deleting files, make a separate backup. Deleting a configuration, disk, snapshot, memory, or state file can prevent the VM from opening, remove access to snapshots, or discard unsaved running state.

Troubleshooting File-Related Problems

The VM does not open after it was moved or copied

The .vmx file may have been separated from its referenced .vmdk files or other required VM files. Verify that the complete VM folder was moved together, then open the VM's .vmx file in VMware Player.

A snapshot is missing or inconsistent

The snapshot metadata or state files may be missing, moved, or mismatched with the VM's disk chain. Avoid deleting or selectively restoring .vmsd and .vmsn files. Keep all snapshot-related files together and restore them from a consistent backup when necessary.

The VM cannot resume from suspension

The .vmss file or associated memory-state data may be unavailable or damaged. Removing suspend-state files discards resumable state and may require starting the VM from a powered-off condition instead.

The VM starts but an error needs investigation

Locate vmware.log or the VM-specific log file in the VM folder and review the most recent messages. Logs can reveal device, configuration, startup, and crash-related details.

Exam-Relevant Summary

• .vmx is the primary virtual machine configuration file.
• .nvram stores virtual BIOS or firmware state.
• .vmdk stores the guest's virtual hard disk contents.
• vmware.log records runtime activity and diagnostic information.
• .vmem is associated with virtual memory or paging state, not permanent disk storage.
• .vmsd stores snapshot metadata.
• .vmsn stores snapshot execution state when applicable.
• .vmss stores suspended VM state.
• A complete VM folder is normally the correct unit for copying and backup.
• Power off the VM before copying, relocating, or manually changing its files.

For related study, see Virtual Machine Files.