This error can occur when a tape drive is offline or when a device has been powered off or removed from the system.
For tape drives, make sure the device is connected, powered on, and toggled online (if applicable). For disk and CD-ROM drives, check that the device is connected and powered on.
With all SCSI devices, ensure that the target switch or dial is set to the number where the system originally mounted it. To inform the system of a change to the target device number, reboot using the -r (reconfigure) option.
This message results from I/O to a special file's subdevice that either does not exist or that exists beyond the limit of the device.
The symbolic name for this error is ENXIO, errno=6.