Category Archives: Linux

Chmod Files and Folders Differentially

I am sure you have had situations where all the files and folders in a subdirectory are accidentally changed to the wrong permissions.

Basic permissions of the files on a website, so visitors can interact: 644

== Files can be read but nobody is allowed to write (edit) the files but the owner.

Owner | Group | Others
R W -  | R – -   | R  -  – ====

R=Read, W=Write, X=eXecute

To get the octal permission number (i.e.644) which is additive

R=4, W=2, X=1 (“-” also means zero)

Read more

Virtual Web Servers: Apache2 on Debian

This is a short How-To about setting up multiple domain names, or sub-domains on Debian Squeeze using Apache 2.2
The following is the actual configurations of a working server with 2 subdomains on it.
It throws an error that does not stop it from working.


#=======snippet from apache2.conf

# Include generic snippets of statements
Include conf.d/

#=======Contents of conf.d directory=======================
wolf@SERVER-01:/etc/apache2/conf.d$ ls
charset localized-error-pages other-vhosts-access-log security virtual.conf

#=======Configuration of virtual.conf=======================

wolf@SERVER-01:/etc/apache2/conf.d$ cat virtual.conf
# running virtual hosts
#
NameVirtualHost *

#======Contents of the sites-available directory============

wolf@SERVER-01:/etc/apache2/sites-available$ ls
default default-ssl legacy

#======Configuration for dev.example.net====================

wolf@SERVER-01:/etc/apache2/sites-available$ cat default

ServerAdmin wolf.halton@ lyrasis.org
ServerName dev.example.net
ServerAlias www.dev.example.net

DocumentRoot /var/www/http/

Options FollowSymLinks
AllowOverride All


Options Indexes FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all

ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/

AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
Order allow,deny
Allow from all

ErrorLog /var/log/apache2/error.log

# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
LogLevel warn

CustomLog /var/log/apache2/access.log combined

Alias /doc/ "/usr/share/doc/"

Options Indexes MultiViews FollowSymLinks
AllowOverride None
Order deny,allow
Deny from all
Allow from 127.0.0.0/255.0.0.0 ::1/128

#========Configuration for legacy.example.net======================
wolf@SERVER-01:/etc/apache2/sites-available$ cat legacy
# This is the settings file for the legacy.example.net site


ServerAdmin wolf.halton@ lyrasis.org
ServerName www.legacy.example.net
ServerAlias legacy.example.net

# Indexes + Directory Root.
DirectoryIndex index.html
DocumentRoot /var/www/legacy/htdocs/

# CGI Directory
ScriptAlias /cgi-bin/ /var/www/legacy/cgi-bin/

Options +ExecCGI

# Logfiles
ErrorLog /var/www/legacy/logs/error.log
CustomLog /var/www/legacy/logs/access.log combined

Nagios Plugins 1.4.16 Installation Notes

Even simple things are hard when you have never done them.
There is a pretty good How-to at http://nagios.sourceforge.net/docs/3_0/quickstart-ubuntu.html for installing Nagios, and plugins, generally. I use Debian, so there may be a few minor differences between an Ubuntu install and my installation on Debian. Mostly I wanted to add a few notes about issues I run into when adding a remote server to the nagios family. You have to do a few things that are not in the instructions.
Before you begin, make sure you have a C-language compiler installed as well as ‘make.’
# aptitude install gcc make
also, your ssl_version in Nagios-Plugins will fail if you do not have libssl-dev installed.
# aptitude install libssl-dev
Your make will continue to fail in an unhelpful manner if you do not now re-run your configure command.
[nagios-plugins-src-dir]$ ./configure --with-nagios-user=nagios --with-nagios-group=nagios
Then run make and it will run properly.
[nagios-plugins-src-dir]$ make
Run make install as root.
[nagios-plugins-src-dir]# make install
Change ownership of the nagios-installation directory to nagios.
# chown -R nagios:nagios /usr/local/nagios
The plugins live in the /usr/local/nagios/libexec folder.

Make sure your nagios@nagiosserver can shell into the nagios@remote-server without a pass-phrase or it will not be able to run "command_over_ssl." I am not yet running the NRE as I understand ssl well enough to use it.

Thanks to Dave Bonnell for the libssl-dev suggestion http://sourceforge.net/mailarchive/message.php?msg_id=29576799

Make sure you ssh into each remote server as nagios@nagiosserver to get past the "Add this server to known hosts" dialog, otherwise nagios will not be able to send test requests automatically.

Nagios: Monitor Remote Disk Free Space

I was working with Nagios-3.3.1, which I love because it shows me everything I want to know and is easier than Zabbix to set up.

Yes, I had to write a shell script to make the config file-generation faster and less troublesome, but after I got that part done, I really started to see a great system.  Nagios sends emails to me when it has an issue, like being unable to access a given server for a test or if the web server is down.  All of this went up in a relatively simple way.  Not as easy as Pandora FMS but still pretty simple, if you consider command-line configuration files simple to edit. Read more

Installing DSpace 1.7 on Ubuntu 10.04

Original wiki entry by

Peter Dietz.

The goal of this guide is to provide a simple path that will get a user up-and-running as quickly as possible. Peter Dietz did a great job with this, however there are issues about setting up DSpace on an Ubuntu 10.04LTS server that I didn’t think were covered well. This is not entirely surprising because there have been two Ubuntu releases since April of 2010, and it is at least because my company doesn’t set up servers on the bleeding edge of Ubuntu development. There may be a switch to Debian at some point. Debian Stable is even more stable than Ubuntu LTS, I must admit, but we are more comfortable with Ubuntu. Read more

Tuning Postgresql-9.0 with pgtune

Presuming you have PostgreSQL-9.0 installed, you are probably running the default configuration. The default configuration is designed to work with a variety of hardware, and is tuned for the weakest possible machine within its hardware profile. The official documentation doesn’t spell out the minimum requirement for the operating systems we use at LTS-Lyrasis, except to say:

  • Special Cygwin instructions may allow you to run versions of Windows older than Windows 20001.
  • On Linux, such as Ubuntu, there are some minimum software version numbers and minimum hard drive sizes
  • The minimum required version is Python 2.2. This came out in December 21, 20012
  • You will need about 100 MB for the source tree during compilation and about 20 MB for the installation directory. An empty database cluster takes about 35 MB; databases take about five times the amount of space that a flat text file with the same data would take. If you are going to run the regression tests you will temporarily need up to an extra 150 MB.3

Pgtune will help you set up PostgreSQL 9.0 to work well with your current hardware.
Read more

Installing OpenSRF for Evergreen-ILS

I am installing Evergreen-ils and getting OpenSRF installed is the second step in the journey.

The Evergreen Project develops an open source ILS (integrated library system) used by approximately 800 libraries.  The software, also called Evergreen, is used by libraries to provide their public catalog interface as well as to manage back-of-house operations such as circulation (checkouts and checkins), acquisition of library materials, and (particularly in the case of Evergreen) sharing resources among groups of libraries.

Read more

Atlanta Linux Freedom Fest 7/23/11

Welcome to the next installment of the quarterly ITT-Tech-Atlanta-South Linux Freedom Fest

The details are as follows:

 


SATURDAY, July 23rd, 2011 ~ 9am to 5pm:

ALE.ORG /
SourceFreedom.com
Linux Freedom Fest

 Hosted by ITT Technical Institute, Atlanta Campus at:

485 Oak Place, Atlanta, GA 30349

( Note: At the corner of Atlanta South Parkway and Oak Place.
Once you get inside, follow the signs to the lab. )

  • Free Linux Discs ~ Free Expert Help
  • Installing and Configuring Linux on your own machine.
  • Seminars by Experts on Various Topics
  • Distros That May be Available: Ubuntu, Fedora, Knoppix, PCLinux
  • Free Drinks and Food Provided By ITT Tech
  • And More!!!

For more information, email wolf@wolfhalton.info today

Contributors include:

ITT Tech Atlanta South, SourceFreedom.com,
ALE.org (Atlanta Linux Enthusiasts)

 

Atlanta Linux Freedom Fest 2/19/2011

More than 60 people attended the ALE.org/SourceFreedom.com Linux Freedom Fest at ITT Tech in Atlanta.

Four speakers provided us with information on how to:

  • Understand the implications of open source and how (and why) to get involved
  • Install and implement the Drupal web site script
  • Maneuver around the command line in the Bash shell
  • Create a basic web page in HTML
  • Write a basic shell script

If you missed the event, sign up at this site or at ALE.org, to be notified when the next Linux Freedom Fest will be happening.

The Atlanta Linux Freedom Fest happens quarterly, so you do not have to wait long for the next one.

If you with to present or help out with the event, contact mhalton (at) itt-tech.edu

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