Most programs and libraries by default are compiled with debugging symbols (gcc option -g) Let me explain what these debugging symbols are and why you may not want them.
A program compiled with debugging symbols means a user can run a program or library through a debugger and the debugger's output will be user friendly. These debugging symbols also enlarge the program or library significantly.
Before you start wondering whether these debugging symbols really make a big difference, here are some statistics. Use them to draw your own conclusion.
A dynamic Bash binary with debugging symbols: 1.2MB
A dynamic Bash binary without debugging symbols: 478KB
/lib and /usr/lib (glibc and gcc files) with debugging symbols: 87MB
/lib and /usr/lib (glibc and gcc files) without debugging symbols: 16MB
Sizes vary depending on which compiler was used and which C library version was used to link dynamic programs against, but results will be similar if you compare programs with and without debugging symbols. After I was done with this chapter and stripped all debugging symbols from all LFS binaries I regained a little over 102 MB of disk space. Quite the difference.
To remove debugging symbols from a binary (must be an a.out or ELF binary) run strip --strip-debug filename. Wild cards can be used to strip debugging symbols from multiple files (use something like strip --strip-debug $LFS/usr/bin/*). Most people will probably never use a debugger on software, so by removing those symbols a lot of disk space can be regained.
You might find additional information in the optimization hint which can be found in http://archive.linuxfromscratch.org/lfs-hints/.