SquashFS

• Consider mksquashfs block size improvements from fedora
• Examine these options for mksquashfs (in order):

-no-sparse -no-fragments -no-duplicates -quiet -no-progress -noappend -no-recovery

• squashfs-tools compresses manpages by default before installing them, so check that as well
• Most distributions use SquashFS for their live CDs
• UnionFS and AUFS are not under active development in the kernel (might still be under development outside the kernel)
• OverlayFS got merged instead into the kernel (and is faster than both UnionFS and AUFS)
• Docker originally used AUFS and then switched to OverlayFS

References

• https://fedoraproject.org/wiki/Changes/OptimizeSquashFS
• https://github.com/AgentD/squashfs-tools-ng
• https://github.com/plougher/squashfs-tools