By: James Gaskin
Single-vendor enterprise computing centers exist only in the minds of somenon-technical corporate executives. IT employees know that every computer roomhosts a wide variety of hardware and software products from a range of vendors.Almost every enterprise network already includes Linux, even if the corporateexecutives of that network don't know it. For instance, modern Web, proxy, andsecurity/firewall servers often run Linux.
Leveraging the open source cost advantages
First, a word of caution: Do not make cost the primary advantage forinstalling Linux systems. Executives will almost always side with what theyknow (Microsoft and Windows) over the unknown (Linux) in spite of major costsavings. Microsoft's PR attacks managed to obfuscate cost of ownership numberssufficiently to make this argument a wash for Linux advocates in mostenterprises. Even strong ROI and TCO arguments may wither under the Microsoftmarketing machine.
Do use cost as an opening gambit, however, by leveraging proposal timing.After Linux makes a positive entrance in one specific task, prepare Linuxoptions when asked for budgetary numbers to replace or consolidate existingsystems or adding new functions. Compare them heads up against comparableMicrosoft systems.
An executive will often choose Linux as a prudent investment overMicrosoft when budgets shrink and deadlines loom after enough proof that Linuxhas performed well for the company in other areas. Many enterprise departments,when squeezed, look for ways to reduce their per processor, per machine, andper seat licensing costs, especially for lower profile network applications.
Web servers
Any existing Microsoft Windows Internet Information Server (IIS)installations should be scheduled for a "security upgrade" and movedto Apache Web server on Linux. Web sites written to design standards willtransfer so easily that switching the server to Linux and Apache may gounnoticed. To be sure, follow this plan:
- Schedule a content upgrade
- Include a security upgrade request
- Upgrade hardware if necessary to match company server specifications
- Mirror the IIS system to a pilot Apache/Linux system
- Develop the content upgrade on the Apache system
- Switch over a day early to clear up any configuration issues before the announced live date
Web content written with Microsoft FrontPage or Active Server Pagesextensions will need extra attention to perform correctly under Apache, and maybe poor candidates for Linux replacement in the short term.
POP3 email servers
Reliable and functional third-party POP3 servers exist for Windowsservers, but Sendmail powers far more email traffic across the Internet thanMicrosoft Exchange does. However, enterprises where Microsoft Exchange providesemail services rarely switch away from Exchange without extreme pressure from acompany owner or executive, or severe pricing issues.
A feature-for-feature Linux-based replacement for Exchange has yet to bedelivered, but that time nears. For instance, SuSE Linux OpenExchangeServer 4.1> provides the majority of Exchange functions and supportMicrosoft Outlook clients. Still, Linux fans fighting Exchange head-on willlose virtually every contest for the next three years unless the company looksfor an Exchange replacement because of Exchange problems, not the attraction ofa Linux alternative.
That said, Linux applications can reduce the high overhead burden of somemail services from an Exchange server. Spam filtering takes far more CPUoverhead and expensive add-on programs inside Exchange than a fronting Linuxserver handling the chore cheaply and quickly. Virus filtering using Linux isanother option with high ROI.
Keep Exchange, but use a Linux proxy server to front the Exchange serverand provide spam/virus filtering outside Exchange. Emphasize the layeredsecurity aspects of the extra Linux proxy server if challenged.
Sendmail (with both open source and commercial versions) and other Linux-based emailapplications can provide cost-effective spam and anti-virus filtering for largenumbers of users. Linux offers a variety of mail transfer agent applicationsbeyond Sendmail, including Postfix,Exim, and Qmail.Remote offices that currently use the POP3 protocol rather than a proprietaryExchange client can make the move to a Linux system without missing a messageor even realizing a switch occurred.
One report from a bank detailed taking a PC slated for disposal andinstalled Linux and SquirrelMail toprovide Web-based email. This new email service allowed bank employees to viewemail through their Web browser, but more importantly, it offered a way aroundthe bank's management-imposed limit of 2MB storage per individual mailbox.Adding a Linux server with Sendmail to a resurrected PC broke through thatbarrier for employees so well that the bank tried SpamAssassin as a complement to thenew Web email. Remember that pattern: pilot project becomes accepted quicklyand the next Linux success comes soon after.
Other common Web e-mail applications running on Linux include Horde and NeoMail. Many ISPsprovide one or sometimes all three options on their Linux servers.
DNS,DHCP, and LDAP servers
Microsoft's Active Directory (AD) needs a stout Domain NameService (DNS) server to run properly, but Microsoft has yet to produce one thatfollows standards well enough to interoperate with the rest of the world. TheDNS services built into every Linux distribution offer improvement.
Dynamic Host Configuration Protocol (DHCP) servers inhabitevery router, network-attached storage, and file server box, but large networksneed distributed yet coordinated DHCP. Many DHCP options exist for Linuxservers, including an IPv6 version ready for download onSourceForge.net.
Identity management and authentication service providersoffer many schemes (AD, Novell Directory Services/eDirectory, Sun ONE IdentityServer, etc.), yet LDAP remains the authentication glue for many enterprisenetworks. LDAP (Lightweight Directory Access Protocol) services power security,access to network resources, and email distribution, but remains low-profile(until it breaks). Because reliability and security rate high on the must-havelist for LDAP servers, Linux options fit the bill for many companies. DNS,DHCP, and LDAP servers can be dropped onto a network with no changes necessaryto clients using those services if the clients follow protocol standards.
File and print servers
To begin integrating Linux file and print servers, identify systems wherelicensing issues complicate continued use. For most companies, this meansWindows servers, for which companies must pay license renewals at a high dollarvalue even if the server no longer provides a high value return to theorganization. Many Windows servers debuted running applications that have nowmigrated to other servers or have been discontinued. When that happens, thelicense cost becomes high for a standard file and print server, which is theonly function still performed. Target these systems for conversion andconsolidation to Linux.
Samba is one of the most successful Linux(or at least non-Microsoft) third-party initiatives. Every Linux serverdistribution includes Samba services ready to support large numbers of file andprint clients running Microsoft Windows, and will do so with lessadministrative overhead than a comparable Microsoft Windows server. Samba onLinux supports the SMB/CIFS (System Message Block/Common Internet File System)used by Microsoft for networking and can act as a Windows PDC (Primary DomainController).
To convert an older Windows server performing primarily file and print services,start a project along these lines:
- Schedule a file server upgrade
- Include a security upgrade request
- Consolidate servers when possible to take advantage of larger and faster disks and increase manageability
- Integrate the Linux server into the Active Directory as the older Windows server (if replacing one to one)
- Learn to handle winbind, the Samba user and group resolving service
- Rename the old Windows server, with file access limited to administrators
- Log out all clients and transfer the file system over the network
- Compare the file systems
- Switch over for several days before disabling the older server
Active Directory doesn't always deal properly with transferred files andownership rights. Verify both before letting users back on the new file server.
Inside the Windows networking world, Linux file systems with Sambaservices appear as a normal Windows file server. Linux clients running Samba(included with every desktop distribution) can access existing Windows fileservers as Windows clients, and the new Linux servers via traditional Linuxnetworking protocols.
Linux offers two printing advancements which fit well into enterprisenetworks: Samba handles Windows printing in place of Windows servers, and the IPP Internet Printing Protocol. Printingflexibility for all manner of clients remains an elusive goal, especially inmixed environments. Many Linux distributions (and Apple) support the Common UNIX Printing System (CUPS).
Linux-powered appliances
Linux provides a variety of embedded software and development tools forcustomizing operating systems for appliance use. Finding a modern networkappliance not running Linux is harder than finding a desktop computer not runningWindows.
Many people consider the best appliance to be an obsolete PC with amodified Linux distribution. This provides low hardware cost and moreconfiguration options than the standard Linux hardware appliance.
Several Linux distributions provide excellent firewalls or secure routersusing minimal PC hardware. Many will run on any Pentium processor with 64MB ofRAM, minimal hard disk space, and two network adapters. Some of these minimalhardware firewalls are:
- Coyote Linux Wolverine
Gibraltar firewall/router- Sentry Firewall CD
Most smart Windows technicians now carry a copy of the Knoppix CD, which boots on almost every PCwith a CD-ROM drive and reads and writes to NTFS (NT File System). Knoppix evenboots from some USB and FireWire CD-ROM drives, making it even more handy tohave in the troubleshooting backpack.
Storage
Network-attached storage (NAS) devices have become a popular departmentalsolution for constantly expanding content. Again, embedded Linux dominates themarket in storage appliances, and they often rely on Samba.
Flexibility has become a main selling point for Linux storage appliances.Every standard Linux distribution supports Windows SMB, Windows CIFS,AppleTalk, and NFS. Windows-based storage solutions rarely cover this wide arange of clients. When maneuvering for a new storage installation, verify thatdepartments that have non-Windows clients are supported.
Converting an existing file server into NAS can be done with any Linuxserver distribution. There are at least two companies offering otheralternatives, using embedded or highly customized Linux:
- NetMax
- ReByte
Adding Linux-based storage to an existing Windows network, using Samba oranother option, has a high success rate.
Backup
The flexibility demonstrated with storage devices makes backup systemsbased on Linux valuable to many companies. As vendors move towardnetwork-attached disk-to-disk backup devices, and disk-to-disk-to-tape,embedded Linux operating systems once again rise to the occasion.
For enterprise use, leverage Linux storage devices as intermediate backupservers. Gather backup data via disk-to-disk transfer to the Linux station,then use common Linux tape backup options: mt and tar.
Corporate executives expect backup devices to have non-Windows operatingsystems, so this is another easy step in Linux integration.
Clusters, grids, and supercomputers
No enterprise today believes acceptable availability means 23x6. Highavailability through clusters or grid computing has become increasinglyimportant to companies in all types of business beyond the HA early adopters.
IBM mainframe Linux options include clusters within a single hardwaresystem. The Linux High Performance Computinglist over 25 Linux cluster vendors waiting to supply products from a singlequote form. Another source of information is the LinuxClustering Information Center.
Stepping up from big iron, some businesses now look to supercomputers tosolve business problems. Executives who check the Top 500 Supercomputer Sites will see Linuxmentioned as the driving software force in system after system. When it reallyis rocket science, drop the NASA name for validation and use its newLinux-powered supercomputer as an example.
Clusters often solve a specific business problem and don't necessarilyinteract with the majority of the user community. This specialization, alongwith the high cost of infrastructure for the new cluster, makes executives morewilling to sign a Linux dotted line.
Taking over the desktops
People say about art that they "know what they like." Artistsknow the truth: people only like what they know.
Many Linux fans believe the desktop matters more than the server room, anddemand faster integration of Linux desktops into their company network. Thistactic in sports is called pitting your weakness against your opponent'sstrength. This tactic will not succeed in the next two years. Although majorhardware suppliers (Dell, IBM, HP) advertise Linux as a desktop operatingsystem option, their sales numbers are minuscule.
That said, there are ways to begin integrating Linux systems into thedesktop and laptop mix. Handled poorly, however, this effort will set backLinux integration across the enterprise.
Desktop areas to avoid
These types of situations will not give way to a Linux desktop within thenext few years:
- Strong Exchange or Notes users
- Custom-written or highly customized applications for specific functions
- Users relying on cross-application macros (but these people will need virus help)
- Companies with heavy investment in Microsoft's client management server software
Emulators for Microsoft Office fans
Emulation software to enable Linux distributions to support MicrosoftWindows applications, like Win4Lin, CrossOver Office, and WINE, are now showing success. Mosthigh-profile Windows applications can be supported on a Linux desktop afterconfiguration. The top 10 applications labeled critical by large companies workquite well under emulation. However, that will not spur a migration.
This attempt to integrate Linux desktops into a corporate environment willnot provide large numbers of conversions. Users restricted to certainapplications will have success, but users free to choose their own softwarewill always find exceptions to the emulators.
Leveraging open source applications
Microsoft Office locked down the corporate desktop years ago, but some oftheir chains are slipping. Comparable office application suites from OpenOffice.org and Sun with StarOffice have wonmore advocates on Windows desktops than Linux desktops. After all, pricing andlicensing terms for Office are more onerous than for Windows XP Professional,the corporate desktop of choice.
Both OpenOffice.org and StarOffice suites have Windows and Linux versionsthat perform exactly the same on corporate computers and Linux systems. Othersjoining the cross-application list include:
- Mozilla Firefox
browser
- Mozilla 7.53 browser
- GAIM's multi-protocol instant messaging client,
- The GIMP graphics editor
How pervasive have these cross-platform applications become in largecompanies? Forrester Research found the 61 percent of 140 North Americancompanies used open source applications. OpenOffice.org, MySQL (a cross-platform database application),and JBOSS lead the open sourceparade.
Only companies with the most arcane Microsoft Office custom programmingwill not be able to switch to OpenOffice.org or StarOffice. MySQL databaseservers run on 20 different server platforms and have a well-earned enterprisenetwork reputation.
Once companies see the quality of Mozilla, OpenOffice.org, MySQL and theother open source programs, Linux testing will be an easy next step.
Summary
Linux systems are rapidly becoming part of the approved mix oftechnologies used to provide business services securely and cost-effectively.Since Linux systems already exist in some corner of virtually every largeenterprise network already, the integration process is underway. However,mishandling early projects could derail the integration in some companies.Build a foundation of Linux success this year and begin to reap the benefits ofproduction Linux installations the next.
IT managers need cost-effective and secure platforms, and Linux providesboth. Executive management needs to learn to trust Linux, and that will happenas more Linux products provide services for their company. Whether the companybuys Linux "on purpose," or the Linux systems come through a morecovert route, every company will learn they have Linux in place.
Integration, by definition, is not a conversion. Integration is theprocess of adding one technology to the existing corporate network andtechnology profile. Demonstrated competence for existing Linux systems willpave the way for an increasing number of Linux systems in every company overthe next three years.
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