It looks like both those packages do the same, or similar, things:
Code:
[root@rhel5current-2 ~]# yum info sos
Loading "rhnplugin" plugin
Loading "installonlyn" plugin
Setting up repositories
rhel-i386-server-5 100% |=========================| 1.4 kB 00:00
rhel-i386-server-vt-5 100% |=========================| 1.4 kB 00:00
rhn-tools-rhel-i386-serve 100% |=========================| 1.2 kB 00:00
Reading repository metadata in from local files
Excluding Packages in global exclude list
Finished
Installed Packages
Name : sos
Arch : noarch
Version: 1.7
Release: 9.1.el5
Size : 381 k
Repo : installed
Summary: System Support Tools
Description:
SOS is a set of tools that gathers information about system
hardware and configuration. The information can then be used for
diagnostic purposes and debugging. Sos is commonly used to help
support technicians and developers.
Code:
[root@rhel5current-2 ~]# yum info sysreport
Loading "rhnplugin" plugin
Loading "installonlyn" plugin
Setting up repositories
rhel-i386-server-5 100% |=========================| 1.4 kB 00:00
rhel-i386-server-vt-5 100% |=========================| 1.4 kB 00:00
rhn-tools-rhel-i386-serve 100% |=========================| 1.2 kB 00:00
Reading repository metadata in from local files
Excluding Packages in global exclude list
Finished
Available Packages
Name : sysreport
Arch : noarch
Version: 1.4.3
Release: 13.el5
Size : 22 k
Repo : rhel-i386-server-5
Summary: Gathers system hardware and configuration information.
Description:
Sysreport is a utility that gathers information about a system's
hardware and configuration. The information can then be used for
diagnostic purposes and debugging. Sysreport is commonly used to help
support technicians and developers by providing a "snapshot" of a
system's current layout.
On my system, sos was installed during the OS install, but sysreport is not. Likely the same is true in your case (check the output of rpm -q sos and rpm -qa sysreport). If that is the case, it makes we wonder why sysreport is being requested by a yum update. Perhaps CentOS got something wrong?