Space saved on /usr/src

Last Updated on Saturday, 10 May 2008 11:27 Written by Administrator Thursday, 01 May 2008 10:19

This text illustrates the space saved by putting you /usr/src files on a compFUSEd mount. It is worth doing this since you are not compiling 26 kernels everyday, are you?

The numbers below are obtained using zlib for the compression.

localhost ~ # ls -l /usr/src/linux-2.6.14-mm2/ total 2904 -rw-r--r-- 1 root root 18693 Nov 20 08:18 COPYING -rw-r--r-- 1 root root 89297 Nov 20 08:18 CREDITS drwxr-xr-x 54 root root 4096 Nov 20 08:25 Documentation -rw-r--r-- 1 root root 1258 Nov 20 08:18 Kbuild -rw-r--r-- 1 root root 63822 Nov 20 08:18 MAINTAINERS -rw-r--r-- 1 root root 43521 Nov 20 08:18 Makefile -rw-r--r-- 1 root root 109930 Nov 23 11:28 Module.symvers -rw-r--r-- 1 root root 14808 Nov 20 08:18 README -rw-r--r-- 1 root root 3065 Nov 20 08:18 REPORTING-BUGS -rw-r--r-- 1 root root 846413 Nov 23 11:27 System.map drwxr-xr-x 27 root root 4096 Nov 20 08:24 arch drwxr-xr-x 2 root root 4096 Nov 20 09:24 block drwxr-xr-x 2 root root 4096 Nov 20 09:24 crypto drwxr-xr-x 56 root root 4096 Nov 23 11:27 drivers drwxr-xr-x 62 root root 4096 Nov 20 17:26 fs drwxr-xr-x 42 root root 4096 Nov 20 08:56 include drwxr-xr-x 2 root root 4096 Nov 23 11:27 init drwxr-xr-x 2 root root 4096 Nov 20 09:24 ipc drwxr-xr-x 4 root root 4096 Nov 23 11:26 kernel drwxr-xr-x 5 root root 4096 Nov 20 18:48 lib drwxr-xr-x 2 root root 4096 Nov 20 17:24 mm drwxr-xr-x 35 root root 4096 Nov 20 17:42 net -rw-r--r-- 1 root root 52 Nov 20 08:18 patches.txt drwxr-xr-x 9 root root 4096 Nov 20 08:56 scripts drwxr-xr-x 4 root root 4096 Nov 20 09:24 security drwxr-xr-x 16 root root 4096 Nov 20 17:34 sound drwxr-xr-x 2 root root 4096 Nov 23 11:25 usr -rwxr-xr-x 1 root root 5473167 Nov 23 11:27 vmlinux

Look into the backend directory now. In this case /usr/.src_cf look at the size of the files there. System.map goes from 846413 to 225491 bytes and so on. One exception the patches.txt file was 52 bytes and is 64 bytes now...

compFUSEd does not compress small files. They still get an extra 12 bytes long header though, that's why. Overall /usr/src compresses nicely and one can achieve around 50% to 60% of the original size (this includes .o files).

localhost ~ # ls -l /usr/.src_cf/linux-2.6.14-mm2/ total 2904 -rw-r--r-- 1 root root 7098 Nov 20 08:18 COPYING -rw-r--r-- 1 root root 40018 Nov 20 08:18 CREDITS drwxr-xr-x 54 root root 4096 Nov 20 08:25 Documentation -rw-r--r-- 1 root root 638 Nov 20 08:18 Kbuild -rw-r--r-- 1 root root 19413 Nov 20 08:18 MAINTAINERS -rw-r--r-- 1 root root 14001 Nov 20 08:18 Makefile -rw-r--r-- 1 root root 21832 Nov 23 11:28 Module.symvers -rw-r--r-- 1 root root 6238 Nov 20 08:18 README -rw-r--r-- 1 root root 1466 Nov 20 08:18 REPORTING-BUGS -rw-r--r-- 1 root root 225491 Nov 23 11:27 System.map drwxr-xr-x 27 root root 4096 Nov 20 08:24 arch drwxr-xr-x 2 root root 4096 Nov 20 09:24 block drwxr-xr-x 2 root root 4096 Nov 20 09:24 crypto drwxr-xr-x 56 root root 4096 Nov 23 11:27 drivers drwxr-xr-x 62 root root 4096 Nov 20 17:26 fs drwxr-xr-x 42 root root 4096 Nov 20 08:56 include drwxr-xr-x 2 root root 4096 Nov 23 11:27 init drwxr-xr-x 2 root root 4096 Nov 20 09:24 ipc drwxr-xr-x 4 root root 4096 Nov 23 11:26 kernel drwxr-xr-x 5 root root 4096 Nov 20 18:48 lib drwxr-xr-x 2 root root 4096 Nov 20 17:24 mm drwxr-xr-x 35 root root 4096 Nov 20 17:42 net -rw-r--r-- 1 root root 64 Nov 20 08:18 patches.txt drwxr-xr-x 9 root root 4096 Nov 20 08:56 scripts drwxr-xr-x 4 root root 4096 Nov 20 09:24 security drwxr-xr-x 16 root root 4096 Nov 20 17:34 sound drwxr-xr-x 2 root root 4096 Nov 23 11:25 usr -rwxr-xr-x 1 root root 2532840 Nov 23 11:27 vmlinux