Rescuing optical media
Rescuing optical media can be difficult, due to the many incompatible formats and copy protections that were used. CDs are difficult to image at low-level because most drives do not give access to the raw data.
The following is a table of some available disc dumping tools.
|Software||Supported media||Development status||License||Platforms supported||Drives supported||Output format||Latest Version||Website||Notes|
|Exact Audio Copy||Audio CD||Actively developed||Proprietary||Microsoft Windows||Most||wav/flac + cue||1.0 beta 3|||
|X Lossless Decoder||Audio CD||Actively developed||GPL||Mac OS X||Most||wav/flac + cue||20130407|||
|Morituri||Audio CD||Actively developed||GPL||Linux||Most||wav/flac + cue||0.2.0-1|||
|RawDump||GC/Wii Optical Disc||Unmaintained||Proprietary||Windows||Certain Hitachi/LG||"ISO"||2.1|||
|FriiDump||GC/Wii Optical Disc||Unmaintained||GPL||Windows and Linux||Certain Hitachi/LG||"ISO"||0.5.3||||Includes documentation on dumping method|
|cdrdao||CD-ROM||Actively maintained||GPL||Linux and Mac OS X||Most||cue/bin||1.2.3||||Does not properly rip CDs with nonstandard data|
|Trurip||CD-ROM||Unknown||Unreleased||Windows||Certain Plextor||ccd/sub/img||Unknown||||Supposedly supports SafeDisc and other forms of copy protection|
|DiscImageCreator||CD-ROM, GD-ROM, DVD-ROM||Actively maintained||MS-PL||Windows||Certain Plextor/others||cue / multiple bin||20130407||||Believed to produce identical output as TruRip for most discs|
Tools of the trade has a list of other tools for disc dumping.
Redump.org has assembled a guide for disc dumping, available at http://redump.org/guide/.
- In most cases you can just create an ISO image with k3b.
- Using ddrescue (
ddrescue -b 2048 -n /dev/sr0 image.iso image.logand so on) you can make an exact copy of any DVD/CD; intentionally corrupt sectors will just be replaced by zeros.  You then need to remove encryption (including region protection) with dvdbackup. 
- Some people report good results with k9copy, not available in all repositories.
- See also this blog post which covers the preservation of CD-ROMs and DVDs using the readom tool, and audio CDs using cdparanoia.