i think you'll need to re-read the man pages on prelink. specifically, the -y or --md5 or --sha options. that is essentially what rpm -V does, it does an "undo" of the prelink to verify the original binary file's hash; which will be the same for the same version of software from the same package. doing an md5sum/sha1sum on prelinked binaries is meaningless now.
i know this whole 'prelink' thing throws people off the first time they encounter it. especially if you're doing computer forensics and you haven't been made aware of this, it'll drive you nuts until you understand prelink. personally speaking, i think this 'optimization' comes at a cost, but one eventually gets use to it.
hope that helps... -Bond
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Aleksey Tsalolikhin Sent: Wednesday, June 30, 2010 6:00 PM To: CentOS mailing list Subject: Re: [CentOS] How can binaries be different when package versions are identical? (mkfs.ext3 on CentOS 5.4)
I read up on "prelink" as suggested; and used "ldd /sbin/mkfs.ext3" to see what the dependencies (libraries) are.
There are 13 dependencies; file size is the same between servers but md5sum's are different!
Most of these libraries have other libraries they call; I finally drilled down to ld-2.5.so which is statically built.
Same thing: same file size, same datestamp, same package version; but the binary is actually different; yet rpm -V does not complain. Why?
(Both systems are running CentOS 5.4; one was deployed in December 2009, the other in April 2010.)
[root@server1 /lib64]# ls -l ld-2.5.so -rwxr-xr-x 1 root root 139416 Sep 2 2009 ld-2.5.so [root@server1 /lib64]# md5sum ld-2.5.so ad38c69452b3990852c0d3e0ea51a31b ld-2.5.so [root@server1 /lib64]# ldd ld-2.5.so statically linked [root@server1 /lib64]# rpm -q -f /lib64/ld-2.5.so glibc-2.5-42 [root@server1 /lib64]# rpm -V glibc [root@server1 /lib64]#
[root@server2 /lib64]# ls -l ld-2.5.so -rwxr-xr-x 1 root root 139416 Sep 2 2009 ld-2.5.so [root@server2 /lib64]# md5sum ld-2.5.so ddb5ad336c3cf40ee2c69b91ef7bfd04 ld-2.5.so [root@server2 /lib64]# ldd ld-2.5.so statically linked [root@server2 /lib64]# [root@server2 /lib64]# rpm -q -f /lib64/ld-2.5.so glibc-2.5-42 [root@server2 /lib64]# rpm -V glibc-2.5-42 [root@server2 /lib64]# _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos