Questions about CentOS 5

1. Can I install CentOS 5 with just the first CD?

You can do a minimal install that just requires the first CD by performing the following two steps during the installation:

• During the category/task selection, deselect all package categories, and choose the "Customize now" option at the bottom of screen.
• During the customized package selection, deselect everything.

There are reports that more than CD 1 is required in the following case:

• If you use some software raid options (this will also require CD 2 and 5)

When the anaconda installer notes that additional disks will be required, but you desire a one CD install, the quick answer is one or more of the following approaches:

• Trim back and do a minimal install. Then once the install is up and running, pull in more packages with yum, and add more options later.

• Use the method: linux text ( Note: you cant do a minimal install using the Text mode, you *must* use the GUI mode if you are looking to install the minimal package set)

If you want to avoid using more than one CD, but want to install more than just the minimal set of packages, you could also consider doing a network installation. A network installation ISO (called boot.iso) is available from the 5/os/<arch>/images/ directory on CentOS mirrors.

2. What kernels are available?

CentOS 5 provides the following kernel packages:

• kernel: Contains the 'normal' kernel. This kernel includes support for both UP and SMP machines.

• kernel-PAE (x86-only): Contains a kernel with support for 64GB of memory on x86 systems through Physical Address Extensions (PAE). Only x86 CPUs that support PAE can run this kernel. This kernel is provided because x86 systems can't address more than 4GB of memory without PAE extensions.

• kernel-xen: Contains a Linux kernel that runs on the Xen hypervisor, for both privileged (dom0) and unprivileged (domU) domains. The Xen kernel is compiled with PAE support.

Additional kernels that have some more options enabled are available through the CentOSPlus repository.

3. Bind is broken in CentOS 5

No, it's not. Yes, it looks like it, as bind-9.3.3 in CentOS doesn't install the config files anymore, at least not, where you would expect them. That was a deliberate choice by our upstream vendor. See this bugzilla entry.

Basically you can just copy the example files from /usr/share/doc/bind-9.x.x/sample/etc/ and /usr/share/doc/bind-9.x.x/sample/var/ to start your own configuration from.

Or you can use system-config-bind to set things up.

Documentation on bind can be found in the Deployment Guide, see Chapter 16.

4. yum groupinstall "GNOME Desktop Environment" complains about a missing libgaim.so.0

This actually is a bug from our upstream provider, see this bugzilla entry.

You can work around that with yum --exclude=nautilus-sendto groupinstall "GNOME Desktop Environment".

This bug will be fixed in CentOS 5.3

5. How do I change my server's name

Running as root:

• hostname acme.dev.nul

(assuming you wish to name the host: 'acme.dev.nul'), and adding or editting the "HOSTNAME=" line in:

• /etc/sysconfig/network

appropriately will do the trick.

Some applications also want to be able to do a lookup of hostname to IP, and for that purpose, editting /etc/hosts is often done. Another and better solution to that second question is to place the server in an environment with a working forward and reverse DNS and letting the initscripts manage the matter. We just answer the question about changing a server's name here.

See also the file documentation concerning the initscripts, which in the first instance handle the setting of the server name based on the values found in /etc/sysconfig/network or /etc/sysconfig/network-scripts/ifcfg-ethX:

• rpm -ql initscripts | grep doc

6. How long will CentOS 5 be supported?

We intend to support CentOS 5 until Mar 31st, 2014 The current plan is this:

• Full Updates (including hardware updates): Currently to Mar 31st, 2010

• Maintenance Updates Apr 1st, 2010 - Mar 31st, 2014

  Full Updates

  During the Full Updates phase, new hardware support will be provided at the discretion of CentOS via Update Sets. Additionally, all available and qualified errata will be provided via Update Sets (or individually {and immediately} for Security level errata.) Update Sets normally will be released 2-4 times per year, with new ISOs released as part of each Update Set. In the 5.x numbering scheme, the .x is the number of the Update Set.

  Maintenance Updates

  During the Maintenance updates phase, only Security errata and select mission critical bug fixes will be released. There will be few, if any, Update Sets released.

7. How do I disable IPv6?

• Edit /etc/sysconfig/network and set "NETWORKING_IPV6" to "no"
• Add the following to /etc/modprobe.conf :

alias ipv6 off
alias net-pf-10 off

• Run chkconfig ip6tables off to disable the IPv6 firewall

• Reboot the system

8. What is the root password of the CentOS 5 Live CD?

No password set for root (as of CentOS-5.1)

9. The content of /etc/redhat-release does not change after I upgraded to a new release?

Starting from CentOS 5.1 the Upstream OS Provider will be providing updates for each point release (5.1.1,5.1.2 ...) for a period of time next to the latest version of the 5 series.

To know in which release you are the CentOS team will be using the following scheme. If the /etc/redhat-release file contains "CentOS release 5 (final)" then you are on the latest point release of CentOS (5.1 at the time of this entry).

If it contains "CentOS release 5.1.z (Branch)" for example then you are in the update release stream for the 5.1 series and you will not move to a newer release without manually telling yum to do so.

To actually verify on what release you are, run the command rpm -q centos-release.

10. When will CentOS 5 for ''your favorite architecture'' be released ?

Now that CentOS 5.1 for i386 and x86_64 has been released the developers have indicated that this is the planned order of release of other architectures : ia64 (Itanium), ppc (PowerPC, POWER), sparc.

11. Is PHP 5.2.5 released for CentOS?

Short answer: No.

A bit longer answer: No. As with each other program in CentOS, the version numbers of released software will not change over the life time of a CentOS product. CentOS 5.0 contained PHP 5.1.6, and that is the point version PHP will stay at for the life time of CentOS 5. It is possible that upstream or the CentOS team decides to push a newer version into some additionial repository. But there are no such plans at the moment.

12. Where do I get the package signing key for CentOS 5?

You need to install the CentOS RPM signing key. It is not installed as part of the base system install for security reasons. This provides you the opportunity to validate the key before installing it on your system. RPM has the capacity to retrieve the key from a Centos Mirror:

rpm --import http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

(as root) will install ('import') the CentOS 5 package signing key for RPM to use to confirm a validly signed package. Please note that it is safer to import the copy of the key from the install ISO media. It is in the root directory of each ISO, as RPM-GPG-KEY, and the same key is present on disc 1 as RPM-GPG-KEY-CentOS-5. The reason this is safer is that a CD is immutable media, and when you verify ISO MD5SUMs, you are implicitly also verifying the key. As a backstop, this key is as follows:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.2.6 (GNU/Linux)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=o/Mx
-----END PGP PUBLIC KEY BLOCK-----

If there is any question as to the validity of the key, please enquire; if a forged key is encountered, please send details, and return contact details to reach you to: security@centos.org

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