The current tar.xz compression code is a burden since it literally takes hours. Currently building VBox and KVM images until upload finished therefore takes more than a day.
Using tar --xz and --mtime="2014-05-06 00:00:00" so the archives are deterministic.
-S, --sparse handle sparse files efficiently
The replacement requirements:
- faster than current one
- handle sparse files efficiently
- currently the result of the compression is reducing the a sparse file with a real size of ~ 4.5 GB (and apparent size 100 GB) workstation qcow2 file to ~ 1.5 GB tar.xz.
- the new file size should be similarly small
- (not 100 GB reduced to ~ 30 GB)
The priority is high, since this reduces my motivation to create Non-Qubes-Whonix images.