When accessing an ESXi host directly via the console—such as through Dell iDRAC, HP iLO, or another remote management tool—you can connect an ISO image. However, you’ll need to address the fact that the medium doesn’t automatically appear as a volume in the shell. By loading the iso9660 kernel module and manually mounting the device path, you can still access the CD-ROM drive within the shell session. The following guide outlines the precise steps and also covers how to properly disconnect the medium after use. This is especially useful when, for example, you need to manually install drivers to restore network cards and remote access after making changes.
Why manual mounting is necessary
Typically, ESXi hides the virtual CD-ROM drive connected via the remote console from the host’s file system. This is because the host doesn’t automatically expose the ISO image through standard volume mounting. The kernel requires the iso9660 module to interpret a CD-ROM’s file system, and the mount process must be initiated manually via the Virtual Storage Interface (vsish). With these two actions, the ISO image becomes a regular entry under /vmfs/volumes and can be copied or examined like any other drive.
Connect the ISO via the remote console
The first phase occurs outside the ESXi shell, on the physical server’s console. The interface varies by manufacturer, but the underlying principle remains the same:
- Open the management interface (e.g., iDRAC, iLO, IMM, or CIMC).
- Navigate to Virtual Media → Connect Virtual Media.
- Select the desired CD/DVD image and link it to the server’s virtual drive.
After completing this step, the remote console recognizes the ISO image, but the ESXi host does not yet detect it.
Verify that the drive remains hidden
To document the current state, connect to the ESXi host via SSH and list the volumes:
ls /vmfs/volumes
You should see that the newly connected medium is not listed. This is normal for an ISO image that is only connected to the remote console.
Load the iso9660 kernel module
The shell requires the iso9660 module to decode the CD file system:
vmkload_mod iso9660
If the module is already loaded, running the command again simply creates a harmless duplicate and doesn’t cause an error.
Determine the device path
The device path is provided by the multipathing tool (esxcfg-mpath). Run the following command to get a clear list:
esxcfg-mpath -l | grep -i cd-rom
The output includes a path like /vmfs/devices/disks/naa.6000c29e.... This path will be needed for mounting later.
Mount the drive within the shell
With the module loaded and the path known, you can register the volume using vsish:
vsish -e set /vmkModules/iso9660/mount /vmfs/devices/disks/naa.6000c29e...
Replace the placeholder path with the actual value from step 4. After this command, running ls /vmfs/volumes again will show the ISO image as a readable entry.
Verify that the ISO is ready:
ls /vmfs/volumes
Confirm that the CD-ROM medium appears. You can now copy files, run scripts, or install drivers contained in the image.
Safely disconnect the drive
When you’re finished, reverse the process to keep the host clean:
- Unmount the volume:
vsish -e set /vmkModules/iso9660/umount /vmfs/devices/disks/naa.6000c29e...
- Unload the module:
vmkload_mod -u iso9660
These steps remove the ISO image from the shell and free up the kernel resource.
Summary
Making an ISO image that’s only connected via the remote console accessible within the ESXi shell requires just two short commands: load the iso9660 kernel module and manually mount the device path using vsish. This procedure works reliably on newer ESXi versions as well, providing quick access to tools and drivers without additional storage requirements on the host. Note that the device path may need to be re-evaluated after a host restart, as it can change.
References
https://www.techcrumble.net/2017/05/how-to-mount-the-host-cd-rom-to-the-esxi-shell/