System Administration

File Handlers

  1. Cannot set user id: Resource temporarily unavailable while trying to login or su as a local user in CentOS
  2. Mount an ISO File in Linux
  3. Making ISO using mkisofs


  1. Tweaking the Linux Kernel to manage memory and swap usage
  2. Clearing memory cache

Nagios and Plugins

  1. Installing Check Disk IO Plugins via NRPE on CentOS 5
  2. Incorporating PNP 0.4.x (PNP is not Perfparse) with Nagios 3 and CentOS 5
  3. Installing and checking /proc/mount using Nagios Plugins on CentOS 5
  4. Installing check_mk for Nagios on CentOS 5


  1. Using TurboVNC 0.6 and VirtualGL 2.1.4 to run OpenGL Application Remotely on CentOS

Kick Start

  1. Basic Kickstart on CentOS 6 (Part 1)
  2. Basic Kickstart on CentOS 6 (Part 2)


  1. Recommended /etc/sshd_config parameters for OpenSSH
  2. Speeding up SSH connections
  3. Automate pushing of ssh-copy-id to multiple servers
  4. Helping users to SSH without password into the Compute Nodes manually

Performance Monitoring

  1. Using mpstat to display SMP CPU statistics
  2. Basic Overview and use of NMON on CentOS 5
  3. Using strace as a troubleshooting tool
  4. Compiling Valgrind on CentOS 5
  5. Brief overview of Valgrind usage
  6. Using iostat to report system input and output

Performance Tuning

  1. Using Tuned to tune CentOS 6 System


  1. Configuring CentOS 5 as an SMTP Mail Client with sendmail


  1. Configuring OpenLDAP on CentOS 6 (Part 1)

Environment Modules

  1. Installing and Configuring Environment Modules on CentOS 5
  2. Usage of Environment Modules on CentOS and in Cluster
  3. Installing and Configuring Environment Modules on CentOS 6


  1.  Speeding up kernel crash hang analysis with the kernel log

General Linux Tools

  1. Using the command “ls” options and arguments
  2. MobaXTerm a Swiss-Army Knife for Remote Computing


  1. Fixing out of memory Issues in Rsync


  1. Disable SElinux in CentOS 7