Consider dropping background readahead on boot
Starting Tails 3.9 from DVD is twice slower than 3.8 (3:55 vs. 2:12 on my hardware), presumably because my "common sense" (sic) did not make me filter out enough stuff from the SquashFS sort file. I did not measure things nor look at the bootchart but it seems as if the X.Org startup was blocked for 2 minutes, waiting for the background readahead to complete, which is kinda ironic.
I think we should:
- keep the SquashFS sort file for now, hoping it is still useful
- try removing the part about
config/chroot_local-includes/lib/live/config/0000-readaheadand measure boot time from DVD and USB, both in a problematic case (3.9) and optimal case (like the squashfs.sort used for 3.8)
- if removing background readahead helps, try removing the foreground readahead as well and measure things again