Ask HN: How Did Someone Send Me a CD-R with 3.5GB Written to It?

1 point·ghastmaster··5 comments

You mean a physical CD-R (maybe mislabelled for some reason?)? What does isosize -x /dev/<drive> show? If you cat it to a file is it 3.5GB? Try different drive if possible? Dunno whether sparse files have something to do with it, check with hex editor.

Also see archwiki for optical disk drive for more tools to research.

isosize says it may not be an ISO filesystem. read error on /dev/sr0: input/output error.

More details:

It is a physical CD-R. It has audio files. Here are the folders/files list. Each codec folder contains tracks 1-20 in that format.

-CDA (folder)

-FLAC (folder)

-Full CD (folder) - Contains single file versions of cda, flac, mp3, ogg, & wav.

-Information (folder) -Contains file "CDDB Information: Server error.txt" (0 B)

-MP3 (folder)

-Ogg Vorbis (folder)

-Track 01.wav

...

-Track 20.wav

Dolphin shows the files fine and the device is 'sr0'.'mount | grep -i sr0' returns nothing. 'cat /proc/mounts' yields nothing regarding sr0. sr0 does not show up with 'sudo blkid', but it does with 'lsblk'.

Well, maybe /dev/sr0 is not your disk drive? lsblk -f should show fs info and the drive.

There's no way you could fit actual 3.5G of information on a CD-R. Whatever this is it must be a miscalculation.

I have searched for compression methods to no avail. I suspect the CD drive used has compression built into the driver. I cannot find very little information online about this.

maybe you got a dvd

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