CentOS Remove Old Kernels

Tonight when upgrading a CentOS Linux server it was noted by YUM that 15MB more disk space was needed to upgrade grub and the kernel itself. Below are four quick steps to verify what kernels are installed, install yum-utils if it is not installed already, delete previous kernels and set YUM to remove old kernels…

Technology Insights

IBM Java SDK Install Error: Failed dependencies: /usr/lib64/libstdc++.so.5 is needed by ibm-java-x86_64-sdk-6.0-9.1.x86_64

While setting up a websphere test server I ran into a minor dependency error during the beginning of installing the necessary packages for websphere. The IBM Java SDK RPM on CentOS 6 was complaining about a failed dependency of a libstdc++ library. The RPM I was attempting to install required libstdc++.so.5 and CentOS 6 has libstdc++.so.6 installed by default. All that is required is to install the libstdc++ compat RPM. The information below describes the error in more detail, how I located the package that installed the necessary file(s), and an example of installing the needed package.

Technology Errors

GPG key retrieval failed: [Errno 5] OSError: [Errno 2] No such file or directory: /etc/pki/rpm-gpg/RPM-GPG-KEY-remi

Earlier while upgrading PHP to version 5.3.5 on a CentOS server I copied over the details of the remi repository from another server I had upgraded PHP on. Once I started the transaction all looked well until Yum needed to verify the remi repo RPM GPG key which I had not installed so an error was provided and Yum stopped the PHP upgrade process. You can get around the RPM GPG key error by simply using the –nogpgcheck switch however that is not the correct way to resolve the problem. You should instead install the RPM GPG key and the below example shows how to install the RPM GPG key for the remi repo.

Technology Errors

postfix/smtpd[XXXXX]: fatal: unsupported dictionary type: mysql, Postfix maillog Errors

I recently updated a development server running CentOS and ran into various minor issues including one regarding postfix being compiled with MySQL support. The development server runs ISPConfig for various virtual hosts and after upgrading all the packages on the server which included Postfix I noticed errors in the maillog. Below I describe what the error was in more detail as well as how it can easily be resolved.

Technology Insights

Install rpmbuild On CentOS Linux

I have been working on setting up some new CentOS Linux servers for a company I work for and one of the things I need to do is build a more current version of Ruby than what is available in the YUM repositories. To do this I am going to download an updated version of the Ruby Source RPM built for Fedora and then build the RPM’s from that. One of the commands required to build RPM’s is rpmbuild which is provided by the rpm-build RPM package as shown below.