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Libraries face unique technical issues in maintaining their computer labs. Every day libraries offer the public access to their computers -- sometimes serving dozens or hundreds of people. Library patrons tend to have a very wide range of skills and use the computers for many different kinds of projects. Some people can accidentally delete key files, while other more technically savvy users may change obscure settings for their own personal preferences. Keeping a library full of public access computers running smoothly can be a challenge under these circumstances. This issue becomes especially important when your lab is also used for teaching classes. A class can really get disrupted if computers are crashing, have their hard drives disorganized, or if the instructor has to stop to troubleshoot a problem on a student's machine.

Unlike the business world, in a library most computers should have the exact same configuration. Since they do not belong to any particular individual, there is no need for unique settings, applications, or files. One really helpful procedure to keep library computers running smoothly is a technique called disk cloning.

What is disk cloning?

Cloning is the creation and maintenance of a complete image or copy of a computer's hard drive.

Cloning can radically simplify and streamline the operation of your library computers. In theory, all of your computers should have the exact same software and system, or at least there should be only a couple of different configurations (i.e., a standard configuration, multimedia workstation configuration, a configuration for your older, slower computers, and the like). By creating a clone of the standard system, you can easily wipe the drive and replace it with the standard configuration when somebody does major damage to a system by deleting applications, changing obscure control panels, or who knows what else.

Users of your public access computers can inadvertently cause problems. If a beginner wanders into the Windows system folder and destroys the wrong .dll file, you could easily spend hours troubleshooting the resulting problem. For complex applications like Photoshop, there are many plug-ins and modules that, if changed, can make the program crash or function improperly. People tend to download files from the Internet and save them in random places. Also, should virus infect your system, it could disrupt your lab for days or weeks.

Rather than spend time troubleshooting such problems, you can simply wipe and replace the contents of the entire hard drive. If you teach a class and want to make sure all the computers are functioning, you can automate the process to wipe and re-write all the hard drives in the middle of the night. When you come in to teach the next morning, you can rest assured that every computer works and is in exactly the same configuration as the day before. Your students will see the exact same thing.

Things to watch out for

Disk cloning is not the same as backing up. Backing up is when the contents of a computer are copied in case the hard drive crashes or important files are inadvertently deleted. The purpose of backing up is really to save data and work. Disk cloning assumes that the data is not important -- that the system configuration and applications are what needs to be preserved. In fact all user data is lost when a clone is re-written. Remember that the disk clone you create is the basic configuration for a computer in your library (just as if the computer was brand new and had the software newly installed). If you are going to do disk cloning, your users cannot save any data on the main hard drive. They will need to save it on a server, a second drive, or on removable storage media. Solid policies must be put in place to avoid accidental deletion of data.

Another important issue with disk cloning is that it works much better when all your hardware is exactly the same. Remember that the clone also contains files such as the drivers for your NIC (Network Interface Card), CD ROM, and other peripherals. If you are running a variety of donated computers, you will have to individually install some drivers on machines after you rewrite a drive. Because of issues with NIC drivers and network settings, getting cloning to work properly can be tricky.

An excellent disk cloning software package for the Windows operating system is Norton Ghost. For the Macintosh operating systems now in use --OS 9 and OS X (10) -- there is OS 9's own Disk Copy application, Apple Software Restore, Mac OS X Server, and utilities such as Carbon Copy Cloner, which can be used for a similar effect in both OS 9 and OS X's various incarnations. Apple Software Restore for OS X is an appropriate way to install or reinstall settings in a lab or library environment.

Doing Windows

LabExpert works best if you have at least a Windows 98 network and computers that are very similar in configuration. “Similar” means the same video cards, network cards, and software configurations. The program is really designed for multi-room networks of hundreds of computers, which are all essentially identical and reasonably current. It does not work well with Windows 95 networks or with dissimilarly configured computers.

A better option for libraries is probably Norton Ghost. It's simpler to use and works well with Windows 95, Windows 98, as well as later Windows versions. There are two versions -- a personal edition and a professional edition. The professional version has more features, works via a server/client setup and allows you to create several clones over a network simultaneously. The personal version is only set up for peer-to-peer networking, and does not allow multiple, simultaneous creation of clones.

Norton's white paper on Ghosting, while aimed at the corporate user, is still an excellent overview with two case studies.

Macintosh

There are a number of utilities and software programs for Macintosh computers that can assist you in setting up your library of public access computers.

Mac OS X Server 10.2 gives you tools to help standardize your Mac network. Workgroup Manager gives you the ability to manage users, groups, and computers from anywhere on your network. Use it to create standard desktop configurations, establish and enforce passwords, and control access to hardware, software, and network resources. This application lets you set up application, system, log-in, finder, printer, media, and Internet preferences for a designated set of public access computers.

NetBoot and Network Install let you implement uniform configurations for multiple Macintosh systems. Network Install lets you create a server-based disk image of software you want to install such that all computers on the network find and install the same software. This includes operating system upgrades. With NetBoot, all computers on the network start up with a single disk image on the server rather than system software on their individual hard drives. This allows you to keep all public access computers in a standard configuration.

Third party software such as Carbon Copy Cloner, a utility from Bombich Software, lets you clone an entire OS X installation, or selected folders, to another volume or drive. With the program launched, simply choose a source and destination drive and select the items you want to copy. Give it about 30 minutes or so, and you will have a bootable OS X volume with those items. Version 2.1.6 works with OS 10.2 (Jaguar) while version 1.3.1 works with earlier versions of Mac OS X.

If you're working in OS 9, use the operating system's Disk Copy application to burn your system folder on to a CD ROM. Disk Copy is located inside the Utilities folder in the Applications (Mac OS 9) folder.

• Choose Create New Image from the Image menu, select 663,000K (CD-ROM 12cm, Full) from the Size pop-up menu in the “Save Disk Image As” dialog box, give the image a name, and click Save.

• When the disk image mounts, you'll be asked to initialize it. Use the default Mac OS Extended format to do that.

• Then insert the OS 9 installation disc, run the installer, and select the disk image you created as the destination for the installation.

• Add any other material you want to the disk image and then burn the contents of the disk image to a CD-ROM.

If you're using Mac OS 10.2 (Jaguar), you can use an OS X native command line version of Apple Software Restore (found in the /usr/sbin/asr folder). Bombich Software has an application called NetRestore, which is an easy way to implement Apple Software Restore. NetRestore can restore a master disk image to a computer's hard disk. It can also be used with Apple's NetBoot to automate configurations in a lab-type environment. A complete set of instructions for handling Apple Software Restore in OS X is on the Bombich Software Web site.