Installing EPEL Repository on CentOS

EPEL stands for Extra Packages for Enterprise Linux. This is a massive collection of packages that are very useful for the building of many modern stacks and include many tools for the running and maintenance of systems. The homepage of EPEL is here: You can browse the package set using repoview: EPEL 6: i386, x86_64, ppc64, sources EPEL 5: i386, x86_64, ppc, sources Installing on […]

Setting hostname

#vim /etc/sysconfig/network Use something like HOSTNAME=testarossa.maranello.local to overwrite the default name and domain of the server. e.g. NETWORKING=yes HOSTNAME=testarossa.maranello.local To avoid rebooting issue the following : hostname  testarossa.maranello.local That will set it for the current  session.      

Monitoring connections

To monitor TCP and UDP connections the following command is very useful: netstat -t -u to have a continuous update use the watch command: watch netstat -t -u There is a much stronger tool for real time analysis called iptraf. It is quite self explanatory : at command line run iptraf This tool has many functions […]

Fixing Warning: RPMDB altered outside of yum

What does it mean? The yum message “Warning: RPMDB altered outside of yum.” or, as the yum message said for a few months, “Warning: RPMDB has been altered since the last yum transaction.” means some application has altered the rpm database (installed or removed a package) without going through the Yum APIs. This is almost […]

Setting up NTP server

Setting up NTP is very important for a host of application especially clusters and applications like DBs requiring all the servers to be critically time-wise synced. Install NTP on Red Hat and CentOS 6 $ yum install ntp $ chkconfig ntpd on $ ntpdate $ service ntpd start Install NTP on Ubuntu $ apt-get […]