Hi Folks,

First of all, my system details:

Centos 5.3 64bit
2.6.18-128.el5

I'm trying to install gcc using yum and it says that I should update glibc as well. As glibc is one of the most important libraries in the system, I'm not very in favor of doing so. The version of gcc that yum tries to install from the CentOS repository is:

gcc-4.1.2-46.el5

The version of glibc is depends on is:
glibc-2.5-42

My current version of glibc is:
glibc-2.5-34


My first question:
Can't yum show me gcc version that is compatible with the libraries that are currently installed in my system? Taking into account that glibc is such an important library.

My second question:
Is it possible to have yum install an earlier version of gcc that is compatible with my glibc?

And 3rd and last question:
In principle upgrading the glibc library should not break anything as I suppose it should be backwards compatible with previous versions?

Thanks in advance.

Ok, Centos ONLY supports the most current dot release of any version. Currently Centos5 is moving from 5.3 to 5.4. As we move forward, new capabilities/features are added. In order make use of those resources newer packages are required. You will note that the major revision did not change, you are and will be using glibc 2.5. You are also behind on the kernel, -164 has been around for a couple of months. Centos/REHL keeps the major revisions of most packages and back patches them to be the equivalent(security and hardware wise) to much more current packages. While there will always be the rare exception, you are safe to update. Keep in mind that one should ALWAYS have backups.

Thanks for your response Lazlow.
If I understand correctly, what you are saying is that new features have been introduced in the upcoming 5.4 version, and therefor new packages are required.
What I don't understand is why the new packages for the 5.4 branch are being added to the 5.3 repository? That's more or less how Arch Linux works, continuously releasing new packages in the same repository.

Ok, BECAUSE Centos only supports the most current dot release the default repo location is set to version 5 and not 5.X. There will be no further updates for any of earlier version 5 series(ie support for 5.0,5.1,5.2,5.3 has been dropped). BUT RHEL/Centos is very careful not to change the backbone of any one version in order to maintain maximum compatibility(ie all Centos5.X have the same backbone). Since your initially installed 5.3 has its repo pointing at 5 (not 5.3) it is attempting to bring itself up to 5.4 in order to maintain support. This is exactly how it is supposed to work. When 5.5 is released it will do the exact same thing and update itself from 5.4 to 5.5. Keep in mind that RHEL/Centos main goal is to keep a stable system. This means that this update process is very thoroughly tested.

Then I misunderstood what you meant by the latest dot release.
I didn't know that there was no specific repository for the 5.3 version. Well, for me it's fine as long as everything has been thoroughly tested, although it's a pity that I'm forced to upgraded to the latest "stable" version, which doesn't necessarily mean the latest "secure" version.

Thanks for the explanation.

First there is a specific repo for 5.3(and all the 5.Xs). However it will not receive any further updates of any kind. If you look at the structure of the Centos' repo it may help:

The 5 (not 5.0) is the default setup in your repo call file. On Centos' end the 5 is just a pointer, it points to the most current release(5.4 now).

In fact it is the most secure version, as it has all the most recent security patches applied. Remember RHEL(which Centos is a clone) tests virtually all it's new stuff with Fedora long before it ever reaches RHEL.