Cost savings of open source software
in the server room

An informal case study in K-12 education


  1. What is open source software?
  2. Listing of open source software used
  3. Cost savings versus capabilities gained
  4. Implicit savings in hardware
  5. Other implicit cost savings
    1. Security
    2. Lower virus vulnerability
    3. Upgrade costs
  6. The roadblock to using open source software
  7. A big thanks to OSS developers


This site was mentioned on Slashdot on 2002-11-20. As an avid Slashdot reader I am truly honored. :)
http://slashdot.org/articles/02/11/20/1923249.shtml?tid=146


1. What is open source software?

It is often difficult for people to understand that some of the most secure, reliable, and efficient software in the world is not owned by a company but rather is under an open license. Open source software is software that was developed with the source code freely available to the public. Anyone may download and use the software, and make changes to it as necessary, with the hope that any improvements made by individuals will be committed back to the main source tree so that everyone can benefit from the modifications.

While this may sound like a strange way to develop software, it is surprisingly common and effective. For instance, in May 2003, SourceForge.net (a site that offers free hosting for open source software development projects) was host to 60,000 open source projects with over 600,000 registered developers. Many people who, if asked, could only name two operating systems would be staggered to learn how many free and open source complete operating systems exist in the world (and that there are several free OS's that could run on the very hardware you're reading this web page with).

Although few people in my school division know what Linux is, every one of them uses it indirectly every day. Open source software has a particularly appropriate niche in budget-strapped public education institutions. This document aims to describe the benefits that Harrisonburg City Public Schools has reaped from the deployment of open source software in its server rooms.


2. Listing of open source software used

While certainly not comprehensive, the list below contains a large sample of the free software products that we employ in HCPS. I have attempted to estimate the cost of replacing these free software installations with commercial products. It should be noted that in some cases my estimations are really just wild guesses as to the cost of various commercial solutions. As a general rule I have tried to estimate on the conservative side. Another thing to note is that commercial solutions for a number of the products below often come bundled as one product, making it very difficult to assign individual replacement costs to the items. For instance, most commercial mail server solutions bundle an SMTP server and an IMAP server together while the open source community's philosophy is to create one product for each discrete function.
Software Estimated cost of
commercial solution
Linux distributions
  Red Hat Linux
Linux distribution for i386 (PC) hardware
$150 x 17 = $2550
  YellowDog Linux
Linux distribution for PowerPC (Macintosh) hardware
$130 x 5 = $650
Web server software
  Apache
The most widely used web server on the internet
$500 x 6 = $3000
  PHP
Server-side web scripting language
$700 x 6 = $4200
  MySQL
Structured Query Language database server
$500 x 4 = $2000
  phpMyAdmin
Powerful web-based database administration tool
$100 x 4 = $400
  DataMiner
User-friendly web-based interface for managing database content
$50 x 12 = $600
  ht://Dig
WWW Search Engine Software
$200 x 1 = $200
  Outreach Project Tool
Web-based group project collaboration environment
$500 x 1 = $500
  Claroline
Web-based course management system
$5000 x 1 = $5000
  Phorum
Web-based forum/message board software
$100 x 2 = $200
  phpWiki
Web-based knowledge collaboration tool
$100 x 1 = $100
Mail server software
  Sendmail
Internet standard MTA (Mail Transfer Agent)
$150 x 1 = $150
  Postfix
Mail Transfer Agent
$150 x 1 = $150
  UW IMAP
University of Washington IMAP/POP3 mail server
$150 x 1 = $150
  OpenLDAP
LDAP server for intregrated authentication and directory services
$200 x 2 = $400
  MailMan
Full-featured mailing list manager
$150 x 1 = $150
  Horde Groupware
Web-based email, address book, and calendaring software
$1000 x 2 = $2000
  eL DAPo
Web interface for administering an LDAP directory
$50 x 1 = $50
  DBmail
Database-based email system
$150 x 1 = $150
  Bogofilter
Bayesian (statistical) spam filtering tool
$500 x 1 = $500
Firewalling/Routing software
  netfilter/iptables
Stateful IP filtering system
$1000 x 2 = $2000
Cross-platform file server software
  Samba
File server for Windows clients
$800 x 4 = $3200
  Netatalk
File server for Macintosh clients
$500 x 7 = $3500
Other network server products
  ISC BIND (Berkeley Internet Name Daemon)
Internet standard DNS server
$100 x 9 = $900
  ISC DHCP
Dynamic Host Configuration Protocol server
$100 x 8 = $800
  WU-FTPD
FTP server software
$50 x 3 = $150
  NTPd
Network Time Protocol server for synchronization of computer clocks
$50 x 4 = $200
  Squid
HTTP caching proxy server
$200 x 2 = $400
  rsync
Incremental backup solution
$50 x 12 = $600
Network management and monitoring
  Snort
Powerful network intrusion detection system
$5000 x 1 = $5000
  ACID (Analysis Console for Intrusion Databases)
Web interface for monitoring and querying Snort alert database
Bundled with
commercial products
  NISCA (Network Interface Statistics Collection Agent)
Monitors traffic on switches and routers
$2000 x 1 = $2000
  Nagios
Monitors servers and routers and notifies me of outages via email
$300 x 1 = $300
  Ethereal
Network analysis and packet sniffing tool
$1000 x 1 = $1000
  sntop
Monitors network connectivity
$30 x 1 = $30
  LanLord
Monitors leases on DHCP servers
Bundled with
commercial products
  Webalizer
Web server statistics reporting tool
Bundled with
commercial products

The list above comprises about $40,000 of (roughly) estimated cost savings in software purchases for HCPS.


3. Cost savings versus capabilities gained

The commercial replacement cost of the free software that we currently use is obviously very high. However, if I were forced to deploy commercial solutions for all of the above, you could probably guess that I would trim back what we needed to buy significantly. For instance, if it cost me $1000 per web server for the server OS and web server software, you can bet that I wouldn't be running six web servers in my server room like I am now. Rather, I would cut back and only run one or perhaps two web servers. This makes it apparent that not all of the benefit of open source software deployment in is the form of cost savings; much of the benefit is in terms of capabilities gained. In other words, through the use of free software, I am able to do more than I could if I only had commercial solutions available.


4. Implicit savings in hardware

Linux can do a lot with only a little hardware. Here in HCPS we have a number of Linux servers running on hardware that would be inadequate for commercial server solutions such as Windows 2000 or Mac OS X. For instance, the web server that served this web page to you is running on an old, retired PC that has been recycled after its lifetime as a Windows desktop has passed. If I were to use Microsoft's IIS server software or Apple's Mac OS X, I would not have considered using this piece of hardware as a web server, and I would have needed to buy new hardware. By enabling me to reuse otherwise useless hardware, open source operating systems have saved our school division a considerable amount of money in hardware costs.

To provide a very rough figure on these cost savings, I estimate that I am currently running 14 Linux servers with hardware that would be inadequate for doing the same job with a commercial solution. To replace those servers with new hardware could easily cost well over $30,000.


5. Other implicit cost savings

  1. Security
    Many companies put a lot of effort into assessments of the monetary liabilities of security risks on their networks. Such cost assessment is not as common in public education but nevertheless the possibilities for such costs exist and should not be ignored. If my installations of open source server software are more secure than a commercial alternative (and I believe they are, although a discussion of security issues is beyond the scope of this document), then we have a lower risk of losing data or productive staff time needed to clean up after a security breach.
  2. Lower virus vulnerability
    I am not qualified to provide a full analysis of virus vulnerabilities of various server operating systems, but I think everyone would agree that historically open source OS's have fared far better than... ahem... other operating systems. The HCPS technology staff spends a fair amount of valuable time combatting viruses on our client PC's but a virus infection on a network server can be devastating in terms of data loss, down time, and staff time required for reconstruction. Open source servers that are less vulnerable to virus infections provide cost savings in terms of decreased liability in these areas.
  3. Upgrade or recurring licensing costs
    The cost of a software solution is not merely the purchase price of the software. The usable lifetime of a commercial software product is rarely longer than 4 years, but where server software products are concerned I would contend that the lifetime is even less -- perhaps only 2 years on average. At this point one must purchase a newer product or an upgrade to the existing one. With open source software, updates are continually free, and I am able to keep my servers running the latest software versions without having to worry about whether I can afford the upgrade.


6. The roadblock to using open source software

So you're probably thinking, "If open source software saves people so much money, why isn't everyone using it?" Two words: learning curve. For people who are used to point-and-click administration of their servers, open source software is often bewilderingly complex to install and configure. I'll admit that you have to be somewhat of a geek to even try out an open source operating system such as Linux. The learning curve that must be followed by a first-time Linux user can be very time consuming and frustrating. For many, especially in public education, this difficulty constitutes a roadblock to the deployment of open source solutions in their district.


7. A big thanks to OSS developers

As you have seen from the informal analysis on this page, I (and indeed my school division) owe a huge "thank you" to the thousands of developers and other people involved in open source software projects.


Copyright 2001-2003
Rob Lineweaver
Last Modified: Friday, August 22, 2003
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