mkisofs mastering sparse files - end result file full of zeros

[Graham Leggett]

Hi all,

Using mkisofs as packaged on Redhat Enterprise 9 I mastered a bluray disk containing various virtual machine images. All files were compressed except one, an uncompressed sparse virtual machine image.

After the disk was burned, I compared the files as a routine check, and picked up the sparse file did not match. I would eventually figure out the sparse file on the bluray contained purely zeros, roughly 8GB of them, matching the original length of the virtual machine image.

It seems to be true that:

- attempting to burn a sparse file doesn't work; and

- no errors, no warnings; and

- you just end up with a sparse file of the same virtual size as the original file containing purely zeros.

Is this a known problem?

xorriso 1.5.4 : RockRidge filesystem manipulator, libburnia project.

mkisofs 2.01-Emulation Copyright (C) 2019 see libburnia-project.org xorriso

xorriso 1.5.4

ISO 9660 Rock Ridge filesystem manipulator and CD/DVD/BD burn program

Copyright (C) 2019, Thomas Schmitt <scdbackup@gmx.net>, libburnia project.

xorriso version   :  1.5.4

Version timestamp :  2021.01.30.150001

Build timestamp   :  -none-given-

libisofs   in use :  1.5.4  (min. 1.5.4)

libburn    in use :  1.5.4  (min. 1.5.4)

libburn OS adapter:  internal GNU/Linux SG_IO adapter sg-linux

libisoburn in use :  1.5.4  (min. 1.5.4)

Provided under GNU GPL version 3 or later, due to libreadline license.

There is NO WARRANTY, to the extent permitted by law.

Regards,

Graham

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