VMware ESXi and vSphere Cluster Management

Add a Generic SCSI Device to a VMware Player Virtual Machine

Learn how to map a host-attached physical SCSI scanner, tape drive, or other peripheral to a VMware Player guest and verify permissions, connection, and driver support.

A generic SCSI device gives a VMware Player virtual machine access to a selected physical SCSI device connected to the host. This is a form of passthrough: VMware presents the host hardware to the guest instead of creating a virtual disk image.

SCSI is a storage and peripheral interconnect standard used by hardware such as tape drives and scanners. The host operating system runs VMware Player and owns the physical connection. The guest operating system runs inside the virtual machine and must support the device that you pass through.

When to Use Generic SCSI Passthrough

Generic SCSI passthrough is appropriate when an application inside a guest must operate a physical SCSI peripheral. Common examples include:

  • SCSI tape drives used by backup software.
  • SCSI scanners used by specialized imaging applications.
  • Other host-attached SCSI peripherals supported by both the host and guest operating systems.

Three conditions determine whether the device will work:

  1. The host must detect and recognize the physical SCSI device.
  2. The user configuring or using the mapping must have the required host permissions.
  3. The guest must include a compatible device driver or application-level support.

Prerequisites and Access Requirements

Complete these checks before opening the virtual machine hardware settings:

  • Attach the physical SCSI device to the host and confirm that the host recognizes it.
  • Shut down the virtual machine. Do not change its virtual hardware while it is running.
  • On a Windows host, use VMware Player with administrator-level access.
  • On a Linux host, use an account with both read and write access to the relevant SCSI device.
  • Identify the intended guest and make sure its operating system supports the peripheral.

Host platform | Required user access | Device readiness check

Windows | Administrator-level VMware Player access | Confirm that Windows detects the physical SCSI device.

Linux | Read and write access to the selected SCSI device | Confirm hardware detection and verify the configuring user can access the device.

Add the Generic SCSI Device in VMware Player

  1. Open VMware Player.
  2. Select the target virtual machine in the VMware Player library.
  3. Open the management menu and choose Player, then Manage, then Virtual Machine Settings.
  4. Open the Hardware tab.
  5. Select Add to start the hardware wizard.
  6. Choose Generic SCSI Device from the virtual hardware categories.
  7. Review the list of physical SCSI devices detected by the host and select the correct device.
  8. Choose whether the device should connect automatically when the VM starts.
  9. Finish the wizard to save the new virtual hardware mapping.

The selected host hardware is now represented in the guest as a virtual SCSI device. This virtual device is the guest-visible representation of the selected physical hardware; it is not a VMware disk image.

Choose the Connection Behavior

Connect at power on controls whether VMware automatically attaches the mapped physical device when the virtual machine starts.

  • Enable it when the guest normally owns the device, such as a backup VM that should use a tape drive at every startup.
  • Leave it disabled when the device is needed only occasionally or must remain available to host software most of the time.

Do not allow incompatible host software and the guest to claim the same device at the same time. For example, release a scanner from host-side scanning software before connecting it to the guest. Similarly, stop host workloads that have the tape drive open before assigning it to backup software inside the VM.

Generic SCSI Device Capacity Limit

A single virtual machine supports a maximum of 60 generic SCSI devices. Every mapped physical SCSI device counts toward this limit, whether or not it is currently connected. If the limit is reached, review the VM hardware list and remove unused generic SCSI mappings before adding another device.

Verify Access from the Guest

  1. Start the virtual machine after completing the mapping.
  2. Check that VMware reports the device as connected to the VM.
  3. Confirm that the guest operating system detects the device.
  4. Install or validate the guest-side device driver and application support.
  5. Perform a low-risk test before production use. For example, detect the scanner without beginning a large scan, or list the tape device without starting a backup job.

A successful VMware mapping alone does not guarantee usability. The guest driver, guest application, device state, and host access conditions must all be correct.

Stage | Action | Expected result

Before configuration | Attach the SCSI device, confirm host detection, shut down the VM, and verify permissions. | The host sees the device and the VM is ready for hardware changes.

Hardware addition | Open Virtual Machine Settings, select Hardware, and choose Add. | The Add Hardware wizard opens.

Physical-device selection | Choose Generic SCSI Device and select the intended host device. | VMware creates a mapping for the selected physical hardware.

Startup connection preference | Enable or disable Connect at power on according to the workload. | The VM has the intended automatic connection behavior.

Guest verification | Start the VM, check detection, validate drivers, and perform a safe test. | The guest can identify and use the peripheral.

Practical Examples

Tape Drive in a Backup Guest

An administrator connects a SCSI tape drive to the host and confirms host detection. The administrator maps it as a Generic SCSI Device, enables Connect at power on, and starts the backup VM. Backup software can then detect the drive through a guest-supported tape driver. Host backup or tape-management software must not retain the drive at the same time.

Scanner in a Specialized Application Guest

A SCSI scanner is selected in the Generic SCSI Device wizard. After the VM starts, the guest scanner application checks for the device and performs a small test. The mapping remains disconnected when host-side scanning software needs the scanner.

Permission Preparation on a Linux Host

A Linux user without read and write access to the host SCSI device may be unable to assign or use it successfully. An administrator must grant appropriate device access through the host's normal permissions process. The user can then configure the mapping and verify detection in the guest.

Troubleshooting

The Generic SCSI Device Option Is Unavailable

  • Confirm that the virtual machine is completely shut down, not suspended or still running.
  • On Windows, launch VMware Player with an account that has administrator privileges.
  • Reopen the VM settings after shutting down the guest.

The Physical Device Does Not Appear in the List

  • Check cabling, power, and host-level hardware detection.
  • Verify that the host operating system recognizes the physical SCSI device before starting the wizard.
  • On Linux, confirm that the configuring user has read and write access to the selected device.

The Device Appears in VMware but Not in the Guest

  • Check whether the device is connected to the VM and whether Connect at power on has the intended setting.
  • Confirm that the guest operating system supports the device.
  • Install or repair the required guest driver and application support.
  • Stop host software or another workload that may still have the physical device open.

The Device Count Is Too High

Review the VM hardware list for unused Generic SCSI Device entries. Remove unnecessary mappings. The per-VM maximum is 60 mapped generic SCSI devices.

Quick Reference

For a concise procedure, see the generic SCSI device configuration guide.