Tonight I started to review the learning material for Red Hat System Administration III to prepare for RHCSE exam. I need a machine with GUI, and all my CentOS 7 VMs are headless. So let’s install the GUI on it, shall I? First install epel repo, if it’s not yet installed: Then install the 2 groups: Tip, if “I” can’t remember the names of the groups, I can run this command to list all available groups:...
I have a server running CentOS 6 successfully upgraded to CentOS 7. The only problem I encountered so far is that ‘grep’ doesn’t work. First thing I tried was to reinstall pcre package which provides libpcre.so*. It still didn’t work. Fortunately, someone has posted a solution as the following: Credit: update to Centos 7; libpcre.so.0 No such file or directory
Someone asked this question in one of his blog posts: Yes, I’m seeing something like that now in the my dhdcp logs. Here is the actual message: I think I know why this happened. Basically, the machine with MAC address of ’08:00:27:6e:61:b8′ used to have grab an IP address from the pool. Then later on, I have created a reservation for it. On Centos 7, the lease file is located at: /var/lib/dhcpd/dhcpd....
This post is primarily written to remind myself, an Ubuntu user, to figure out how to find what RPM package provides a file — for example a header file. Today, I’m trying to compile and install R 3.1.3 on CentOS 6 from source code. This R installation is one of the requirements to install Tessera stack. The instruction from the installation page is: Unfortunately, the process failed with ./configure with the complain about missing readline library....
I have been having issues getting X2Go running on a CentOS 6.5 box. It took me a while to figure out that the problem laid with the permission of /tmp directory. I’ll write how to solve the X2Go problem in another post. The recommended permission for /tmp is 1777. Notice that the forwarding ‘1’ is the sticky bit which only allows the owner of the file within /tmp (or the root user) to delete/rename the file....
I need to install pg 0.17.1 gem on a server running CentOS. This is the error message I saw: # gem install pg -v '0.17.1' Building native extensions. This could take a while... ERROR: Error installing pg: ERROR: Failed to build gem native extension. /usr/bin/ruby extconf.rb checking for pg_config... no No pg_config... trying anyway. If building fails, please try again with --with-pg-config=/path/to/pg_config checking for libpq-fe.h... no Can't find the 'libpq-fe.h header *** extconf....
First we need to add the ZFS on Linux repository to our system by installing a zfs-release package as shown below: $ sudo yum localinstall --nogpgcheck http://archive.zfsonlinux.org/epel/zfs-release-1-3.el6.noarch.rpm $ sudo yum install zfs Once, zfs has been installed, we can create a storage pool. There’re many RAID configuration to choose from, and I’m not going to get into it. However, if you want to learn more, you can read this ZFS Administration article which explains in great detail about ZFS RAID(Z)....
When you install CentOS 6 using minimal CD, a lot of packages aren’t installed by default; <strong>cron</strong> included. To install it, After the installation, you can verify that crond is running:
First let me declare that I’m new to CentOS. The folowing is a note to self which demonstrates how we search for a package that provides some commands and intall it using yum on CentOS. When I ran ‘lsb_release -a’, the following message is returned: To fix it, we need to install the package which provides lsb_release command. So, let’s install redhat-lsb package: Wow, it needs to download 86M just to install that package?...