They use compressed file systems.
OpenBSD does not have a compressed file system. I have no interest in writing one.
My LiveCDs/LiveDVDs ISOs are all CD9660 file systems. In the case of Gnome and KDE, due to the number of files involved, there are nested CD9660 file systems used with vnode disks in order to circumvent the limitations of the CD9660 boot loader. MFS file systems are used for /etc, /var, /home, /root, and /dev.
None of these are compressed. Note: The OpenBSD ramdisk kernel, bsd.rd, used for installation and limited rescue, takes advantage of a facility called "crunch". Crunch is used to creates a single executable file out of many individual binaries. This can provide some space savings for executables only. For booting bsd.rd from a variety of limited-space media (such as 1.4MB diskettes), this has advantages. This is not the same thing as a compressed file system and would not provide significant value in this situation.
|