cd/dvd drive unable to mount

berardel · n00b Joined: 03 Mar 2018 Posts: 34 Location: United States

so whenever i try to mount the drive, it will always say something along the lines of "bad superblock" cannot read. no programs can read it either. im using kernel version 4.9.76 and the LG GH24 disk drive. does someone know what i can change in order to make it be readable?

russK · l33t Joined: 27 Jun 2006 Posts: 665

berardel,

what type of disc are you putting in the drive?

Hu · Administrator Joined: 06 Mar 2007 Posts: 23091

What is the output of file -s /path/to/optical/block/device?

berardel · n00b Joined: 03 Mar 2018 Posts: 34 Location: United States

The Doctor · Moderator Joined: 27 Jul 2010 Posts: 2678

You don't mount DVDs or CDs. You just play them. They do not contain a file system.
_________________
First things first, but not necessarily in that order.

Apologies if I take a while to respond. I'm currently working on the dematerialization circuit for my blue box.

berardel · n00b Joined: 03 Mar 2018 Posts: 34 Location: United States

berardel · n00b Joined: 03 Mar 2018 Posts: 34 Location: United States

scdbackup · n00b Joined: 19 Oct 2014 Posts: 23 Location: Germany

I have to contradict the statement by The Doctor.

CDs may have filesystems on them, if they were written as data discs
(CD-ROM). The other main CD format is audio (CD-DA), which is indeed not
mountable and not even readable with the normal SCSI READ command for
storage devices.

Written DVD and BD media are always readable as storage devices. Usually
they contain ISO 9660 or UDF filesystems. UDF is prescribed for
entertainment video players, but not necessarily for general data storage.

Typical examples for CD and DVD with ISO 9660 filesystem are the installation
media images of Gentoo at https://www.gentoo.org/downloads/ .

A special feature of many CD, DVD, and BD types is that they can be unwritten
and thus bear nothing to read yet.

NeddySeagoon · Posted: Fri Mar 09, 2018 10:02 am Post subject:

scdbackup,

For completeness entertainment DVDs and Blurays cannot normally be played or ripped using the filesystem.
Its usually deliberately corrupted or incomplete to prevent that.
Both formats are played using a blocklist, just like CD-DA.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

scdbackup · n00b Joined: 19 Oct 2014 Posts: 23 Location: Germany

Neddy Seagoon wrote:
> For completeness entertainment DVDs and Blurays cannot normally be
> played or ripped using the filesystem.

There may well be obstacles for computer access to the proprietary
content. But other than with audio CD, the video DVD and BD specs demand
an UDF filesystem. (See wikipedia "DVD-Video" and "Blu-ray".)

> Both formats are played using a blocklist, just like CD-DA.

CD-DA has a Table-Of-Content (like all optical media) where the start
and end sectors of the tracks are recorded. (Wikipedia "Compact Disc
Digital Audio".)
Additionally to the track limits, there are "Index" points inside the
CD tracks which one can hop to by an audio player or ripping program.
(See MMC-5, 4.2.3.3 Frame Adressing, ff., and 6.26 READ TOC/PMA/ATIP
Command.)
The Table-Of-Content of DVD and BD does not bear these indice.

My point is that CD, DVD, and BD can well contain mountable filesystems.
But of course one can put data onto them which need special software to
be decoded. Not only by unusual access structures but also by encryption.

(I clearly belong to user group 2: At least 5 ISO 9660 backups per day
on DVD and BD multi-session discs.)