Are Red Hat Enterprise Linux and Fedora Core fundamentally sound?

[Wiktor Rzeczkowski]

Thanks. Yes, prelink seems to have actually been changing the files.
After running prelink to revert its actions the files and their checksums
returned to normal. Enabling/Disabling prelink can be accomplished by
setting, respectively, yes or no for PRELINKING in /etc/sysconfig/prelink
and executing the script /etc/cron.daily/prelink.

Wiktor

On Sat, 10 Mar 2007, Dennis Gilmore wrote:

> Once upon a time Saturday 10 March 2007, Wiktor Rzeczkowski wrote:
> > I did some testing of RHEL v.4 U4 AS, FC3, FC5 and FC6 and seem to have
> > been finding that, soon after a fresh installation of the OS on a
> > non-networked machine, many files were automatically changing. I also seem
> > to have been finding that some time after package update, the files were
> > automatically changing again.
> >
> > /bin/ls is one of the files that were changing. The file is part of
> > coreutils package. The following are MD5 checksums for /bin/ls on the
> > specified RHEL and FC systems immediately after installation of the
> > specified coreutils package (current version). The checksums are computed
> > by 'md5sum /bin/ls' and the versions of OS and of coreutils are displayed
> > by 'cat /etc/redhat-release' and 'rpm -q coreutils' (no quotes),
> > respectively.
> what you are seeing is prelink in action.  from prelink's man page
>
> prelink is a program which modifies ELF shared libraries and ELF dynamically
> linked binaries, so that the time which dynamic linker needs for their
> relocation at startup significantly decreases and also due to fewer
> relocations the run-time memory consumption decreases too (especially number
> of unshareable pages). Such  prelinking  information  is  only used if all
> its dependant libraries have not changed since prelinking, otherwise programs
> are relocated normally.
>
> you are free to disable prelink if you want.
>
> Dennis
>