tree 309f094712c69931fbf0d3552846238ba17c4201
parent ff8035f8482a1ee9f8ef84ef9ee16ab3f2ba9cd2
author Ed Tanous <ed.tanous@intel.com> 1541099757 -0700
committer Andrew Geissler <geissonator@yahoo.com> 1546614924 +0000

Rootfs filesize analysis tool

This commit checks in a tool to be used for analysing the space taken up
in the rootfs, as well as an overnight run from my system.

Most other tools give estimates of the space savings given when things
are deleted by either xz compressing the individual file, and measuring
the cost, or doing some other things.

This script actually attempts to remove the file or folder in question,
and rebuild the squashfs without it, then measure the size savings.  It
loops this over the entire filesystem (excluding symlinks) and sorts the
result by size savings.

It takes a _very_ long time to run (several hours on a very fast
machine) but should give the most accurate answer to "what can we delete
to reduce our flash usage".

Some things that surprised me:
1. Deleting python would save us ~2.7MB in the rootfs size after the
/usr/lib/python2.7 delete (2.2MB), and the libpython removal (500KB)

2. Redfish static data is taking up more space than originally thought
with the latest revisions of the spec.  Filtering the schema files down
to the ones we actually use would probably save us 100KB.

3. keymaps take up 430KB! ! ! !.  In comparison, this is almost exactly
the same size as libc takes on the bmc.  A quick look at the things
shows that they're being pre-gzipped in the filsystem, which means that
the xz compressor can't compress similarities between files.  Might be
something to look at.

4. bmcweb binary weighs in at 425KB.  This can be optimised.

5. /usr/share/www weighs in at 678KB.  We need to get this down.

6. cracklib takes up 217KB.  This seems kinda lame.

Change-Id: I5636ff22009f341a1454afd480f54701c6cf7954
Signed-off-by: Ed Tanous <ed.tanous@intel.com>