dvd-ram-control

dvd-ram-control [OPTIONS] DEVICE

--set-speed <speed> | -s <speed>
    Sets the DVD-RAM read/write speed. <speed> can be a numeric value (e.g., 2, 4, 6), or the keywords 'max' or 'min'.

--get-speed | -g
    Queries and displays the current DVD-RAM read/write speed.

--force | -f
    Forces the operation, ignoring minor errors or warnings.

--verbose | -v
    Increases the verbosity of output, providing more detailed information about the operation.

--help | -h
    Displays a help message and exits.

--version | -V
    Displays version information for the command and exits.

DEVICE
    The path to the DVD-RAM device, typically a SCSI generic device like /dev/sr0, /dev/cdrom, or /dev/sg1.

dvd-ram-control is a specialized Linux command-line utility designed for low-level interaction with DVD-RAM drives. Its core functionality revolves around managing the read and write speed of DVD-RAM media. Users can either query the drive's current speed setting using the --get-speed option or explicitly set a desired speed (e.g., 2x, 4x, or max) with the --set-speed option. This control is crucial for various scenarios, such as optimizing data transfer performance, reducing noise during quiet operation, or troubleshooting compatibility issues with specific media or drives.

The command operates by sending direct SCSI commands to the optical drive, necessitating appropriate system permissions, typically root access, and a properly configured kernel with support for SCSI generic devices (like /dev/sg* or /dev/sr*). It's an integral part of the dvd+rw-tools suite, providing fine-grained control over DVD-RAM hardware beyond what standard file system operations offer.

• Requires a physical DVD-RAM capable drive and media for functionality.
• Typically requires root privileges or appropriate group permissions to access low-level SCSI device files (e.g., /dev/sg*) for security reasons.
• Not all DVD-RAM drives support all speed settings, and some may not allow software control over speed due to firmware limitations.
• The actual achieved speed may be influenced by the quality of the DVD-RAM media and drive's internal mechanisms, potentially overriding the requested speed.
• Proper kernel modules (e.g., sr_mod, sg) must be loaded for device recognition and SCSI command passing.

To effectively use dvd-ram-control, you usually need root privileges or to be part of a group (e.g., 'disk' or 'cdrom') that has direct read/write access to the raw SCSI device files (e.g., /dev/sg* or /dev/sr*). Improper permissions will result in 'Permission denied' errors.

This command is specifically designed for DVD-RAM media. Its functionality, especially speed control, is generally not applicable to other optical disc formats such as DVD-R, DVD+R, DVD-RW, or CD-R/RW, which have different mechanisms for speed and data management.

dvd-ram-control is a component of the dvd+rw-tools suite, a collection of essential utilities for low-level control, formatting, and writing to various DVD formats, including DVD-RAM, on Linux systems. The suite was developed by Andy Polyakov, providing critical functionalities for managing optical drives that extend beyond standard file system operations.

growisofs(1), dvd+rw-format(1), sg_raw(8), sdparm(8)