UNIX/Linux system administration references

  • Introduction
  • User accounts and groups
  • Configuring disk quotas
  • Working with LVM
  • SSH server/client config
  • NFS
  • Setup a CVS repository
  • Setup an SVN repository



NOT only the bare minimum!…

Reference books

  • Æleen Frisch, Essential System Administration, O'Reilly, 3rd Edition, 2001 [x]
  • D.J. Barrett and R.E. Silverman, SSH The Secure Shell: The Definitive Guide, O'Reilly, 2001 [x]
  • and many, many others…

User accounts and groups

# cd /export/eltXXX/disk0/
# mkdir users
# mkdir /users
# useradd [options] <username>
# groupadd [options] <group name>

Configuring disk quotas

SSH server configuration

The SSH server’s configuration file is /etc/ssh/sshd_config.

By default OpenSSH permits users (including root!) to login with their username/password combination.

SSH server configuration file:


To make changes effective, always restart the SSH service:

# /etc/init.d/sshd restart

Prevent root login

Setting in /etc/ssh/sshd_config the PermitRootLogin option to no the SSH server does not allow root to login. You can still use su after you have succesfully logged in as a normal user.

PermitRootLogin no

Limit SSH access to a limited group of users

As an extra security measure, you can create a new group on the server machine and configure the SSH server to allow remote connections only for users member of that group.

AllowGroups <group name>

Setup the SSH server to use certificates for authentication


NFS setup

See the NFS page.

Setup CVS


A nice manaul can be found at


$ which cvs
$ cvs -v
Concurrent Versions System (CVS) 1.11.23 (client/server)
# yum install cvs

Create a repository

Create a CVS top directory e.g. .cvsroot

# mkdir /export/eltXXX/disk0/.cvsroot
# chown cadmgr:mgrs .cvsroot/

All the following instructions must be accomplished by by the user hosting the cvs repository, which should be the cadmgr. Login as cadmgr and then:

cd /export/eltXXX/disk0/.cvsroot
setenv CVSROOT  /export/eltXXX/disk0/.cvsroot
cvs checkout CVSROOT/modules
cvs init


Basic CVS commands

  • cvs checkout project or cvs checkout project/subdir
  • cvs add <filename>
  • cvs remove <file name>
  • cvs commit -m “Versioning text message info”
  • cvs commit -m “Versioning text message info” <filename>

Setup an SVN repository

$ which svn

By default, subversion is not installed on Scientific Linux 6.x

# yum install subversion

Last update: Luca Pacher - Nov 21, 2013