Basics of Initial CentOS/RHEL 6.x Server

ConfigurationWarren Myers

BGLUG 4 Aug 2014

Create a Server Digital Ocean

• Sign in/up (http://bit.ly/1ukcuUK)• Create Droplet (VM)

VirtualBox• Create new VM• Mount OS ISO• Boot and install

First Steps Post Build Turn off unnecessary services

• chkconfig --list | grep ‘:on’• chkconfig <servicename> off

Install any updated packages• yum -y upgrade

Basic sanity on ssh• Create a new user• Give user sudo privileges

visudo Enable wheel group Add user to wheel

• Disallow password authentication for root

Second Steps Post Build Add swap (if you didn’t during install)

• Do you “need” swap? Yes! No! Maybe!

• Partition or swapfile? As root

dd if=/dev/zero of=/swapfile bs=8096 count=524288 mkswap /swapfile swapon /swapfile Add to /etc/fstab

/swapfile swap swap defaults 0 0

Third Steps Post Build User management Configure postfix (or exim or …) Install apps/services you want/need

• Apache/Nginx• PHP• ftp

ftp access should be highly limited Install helpful utilities

• yum -y install screen emacs

What About RHEL/CentOS 7?

Pros• Kernel now on 3.x series• Better virtualization support• Lots of updated packages

Cons• chkconfig doesn’t manage most services• Seemingly-small changes bigger than in

previous version upgrades

What About My Favorite Distro? Ubuntu / Debian / Mint

• Configs similar• Uses update-rc.d instead of chkconfig• Mint isn’t a server distro!

Slackware• Many configs similar• No standard tool like chkconfig

SuSE• Configs similar-ish … but more “European”• Also uses chkconfig

Everything else (Arch, *BSD, etc)• <shrug/>

What About Desktops/Workstations?