As a guess...
I would say that the version of the openvas-scanner that you are trying to install; openvas-scanner-3.2-0.2.el5.art.i386 is different from your currently installed client; openvas-client-3.0.1-1.el5.art.i386
So yum is trying to install some dependencies for the scanner, which conflict with the installed dependencies used by the client. This is forcing yum to try to upgrade everything at once to meet requirements - including openvas-client. Hence why yum is telling you about your already installed openvas-client dependencies.
However... The fact that openldap-clients and net-snmp-utils are listed is suggesting a missing distro repo problem... openldap-clients is an un-versioned dependency from your base installs "updates" repo, so it should be resolved from that. This might indicate that you have disabled your rhel-updates repo, or that your subscription has expired.
try the following to see why you can't install the openldap-clients;
# yum info openldap-clients
Loaded plugins: downloadonly, fastestmirror, security
...
Available Packages
Name : openldap-clients
Arch : x86_64
Version : 2.3.43
if that doesn't work try;
yum --enablerepo=base --enablerepo=updates info openldap-clients
and then try
yum --enablerepo=base --enablerepo=updates install openldap-clients net-snmp-utils
Basically, its starting with resolving your distro dependencies, and then see if openvas-scanner still can't update...
yum
interfaces with the online repository related to your version of CentOS.
rpm
is the package manager and packaging format for applications developed for the Red Hat/CentOS platform. Your rpm
command is installing a packaged that was downloaded and is not part of a yum repository.
In the Windows world, it's like the difference between Windows Update (yum) and downloading a piece of software and double-clicking an installer (rpm).
It also appears as though you're using a version of postgresql that is newer than the one available through the normal CentOS channels ("Base" and "Updates"). The package being installed by the yum command you listed is coming from a different third-party software repository.
It looks like you're using the postgres database packages provided directly be PostgreSQL instead of the ones that come via CentOS. The instructions and reasoning are detailled here.
As a result, you've been asked to prevent the version that's is distributed with CentOS from installing by using the exclude=
statements you listed. This is a precautionary measure to avoid a conflict between the older version of postgresql from CentOS and the newer one you're installing.
Best Answer
This might be really dumb but it should work.