Disk Imaging Tools: Install, Clone, Manage

When I first started working with computers, I often asked a knowledgeable friend of mine for help troubleshooting small problems. When we encountered a problem we couldn't resolve, his solution was to reformat the hard disk and reinstall Windows. At first I was taken aback by such a radical approach, but he swore by complete reinstallations no less than every 6 months. And he was right. Over time, unmanaged changes impair a system's operation, and a fresh start can solve multiple problems. Although technologies such as Group Policy help rein in such uncontrolled changes, some problems aren't worth troubleshooting, especially if a fresh installation is a simple matter of deploying a prebuilt disk image. For simple disk-to-disk copying, you might consider a hardware-based tool such as Diskology's Disk Jockey (see the Web-exclusive sidebar "Disk Jockey," http://www.windowsitpro.com, InstantDoc ID 45964), but to manage machines in the enterprise, you need a disk imaging tool that does more than just copy data.

Disk imaging is the process of making an exact data copy on a partition or hard disk and writing it to an image file or another hard disk. Using disk imaging to provision computers ensures that all your machines start out with identical and clean software configurations. Disk imaging is also called ghosting (after the popular Norton Ghost utility). Although you can still buy Norton Ghost from Symantec (Symantec acquired Norton in 1990), today's disk imaging products do more than the DOS boot disks you might remember.

I tested two products that support sector-based disk imaging: Altiris Deployment Solution 6.1 and Symantec Ghost Solutions Suite. Products that support sector-based disk images can copy and restore partitions independently of the file system, which lets them copy disk partitions and entire disks no mater what file system they contain. Both products also support file-based disk imaging for their supported file systems so you can read and write files directly to the disk image without restoring it to a hard disk.

To test the products, I deployed an image from a source machine to a target machine. I evaluated imaging speed, ease of use, and supported hardware. Finally, I compared the products' advanced features, such as multicast deployment, user data migration, and software package deployment.

Commonalities
Altiris Deployment Solution and Symantec Ghost Solutions Suite both include management consoles, agents for managed clients, client boot media, and Preboot Execution Environment (PXE) server software for booting clients from the network. Both products require that you configure the source machine, use the console and agent or the boot media to take an image of it, and use the boot media or the PXE server to deploy that image to the target machine. Both products can run Sysprep on the source machine prior to imaging so you can deploy the image to targets that have different hardwahttp://www.windowsitpro.com/Article/ArticleID/45964/45964.htmlsee the Web-exclusive sidebar "Disk Jockey," http://www.windowsitpro.com, InstantDoc ID 45964re than the source machine. Both products can change the SID, configure a unique hostname and network settings, and join a domain on deployment. They also let you resize target partitions for supported file systems. Although the products share basic functionality, their advanced features differentiate them.

Altiris Deployment Solution 6.1
Deployment Solution comes in two versions: Deployment Solution for Clients and Deployment Solutions for Servers. Deployment Solution for Servers can manage Windows Server and Linux OSs, supports power control, and can manage Dell, Fujitsu-Siemens, HP, and IBM blade servers by rack location.

Deployment Solution's imaging component, RapiDeploy, includes agents for nonserver Windows OSs and agents for Windows Server and Linux in the server version. You can install the Windows agent from the Deployment Server console and use the agent to remotely perform imaging and other tasks on the target machines. The agent offers unique features such as registry backup and restore and remote desktop/terminal server-style remote control.

For deploying images to new computers, Deployment Solution's Initial Deployment feature uses the PXE server to automatically boot to DOS and run RapiDeploy. For non-PXE hardware, the Boot Disk Creator that Figure 1 shows can create a boot disk that includes DOS and RapiDeploy. The Boot Disk Creator requires that you supply original Windows 9x media, however, so it can copy the required DOS files. Although RapiDeploy will also work from a bootable DOS CD-ROM, the Boot Disk Creator doesn't create ISO images, so you'll have to create your own DOS CD-ROM. Deployment Solution also lets you automate a scripted OS installation for Windows and Linux.

Deployment Solution does more than shuffle disk images between machines. You can add, remove, and edit files on images that contain FAT, Linux ext2/ext3, and NTFS partitions and distribute applications and personalities to managed machines. A personality is a group of files, OS settings, and application settings that you create by using Deployment Solution's migration component, PC Transplant. PC Transplant includes a database of settings for more than 60 applications and can migrate settings between different versions of an application. When you configure a personality template, Deployment Solution's GUI lists warnings for each application so you know its limitations. For example, the software warns you when it can't migrate signatures in IBM Lotus Notes. The Deployment Solution console can also manage multiple deployment servers, so it's scalable—a useful capability because PXE boot and multicast image-distribution packets are usually confined to the local subnet.

Symantec Ghost Solutions Suite
The Ghost Solutions Suite consists of four separate products—Ghost Corporate Edition, Client Migration, DeployCenter, and 3com Boot Services. Despite separate installations, loose integration, and some duplicate functionality, the lineup is a great value, and the interactive tutorials helped me get running quickly with this complex set of products. The Symantec Ghost Console that Figure 2 shows lets you create boot disks and remotely image machines for deployment and backup.

Like Deployment Solution, Ghost Solutions Suite can remotely install its agent from the console or boot machines from a boot floppy disk or a PXE server. The GhostCasting feature multicasts an image to one or more clients at the same time, thereby saving network bandwidth; I found it to be the easiest way to transfer images between the server and client. (Deployment Solution's RapiDeploy also supports multicasting.)

Ghost Solutions Suite's hardware support reflects its maturity as a disk imaging solution. In addition to reading and writing image files from the local disk, from shared network drives, and through GhostCast, the Ghost Solutions Suite DOS client includes parallel and USB cable connections, has built-in support for USB and FireWire (IEEE 1394) mass storage devices, and can write images to a CD-ROM or DVD. Ghost Solutions Suite also lets you use disk imaging as a backup solution for managed clients and can create incremental images to save disk space.

The Client Migration feature migrates user and application settings between PCs and lets users access a Web site to save and restore their settings and files. The administrator can also perform this task automatically via the command line or a script. Client Migration's application settings database includes only about 30 applications—half of what PC Transplant supports—and control over the OS user settings it migrates is less granular than PC Transplant's. The self-service user Web site is a useful feature, but Client Migration is less administrator-friendly if you migrate user settings yourself.

Performance
The Symantec Ghost Solution Suite Implementation Guide claims that Ghost Solutions Suite can image a disk running Windows XP Home Edition and Microsoft Office in less than 1 minute on a Pentium 4 machine with a 7200rpm hard disk. I didn't have the hardware to test this claim, but imaging a 700MHz Mobile Pentium III machine with a 4200rpm hard disk and a similar software configuration took about half an hour when I used fast compression. Although this time beat Deployment Solution's time (which also used fast compression) by 4 minutes, the image file that Ghost Solutions Suite created was 10 percent larger, so your hardware configuration will probably affect performance more dramatically than the software will.

What Should You Buy?
Although their basic operation is much the same, Deployment Solution and Ghost Solutions Suite are differentiated by their features. I was especially impressed with Ghost Solutions Suite's hardware support and incremental imaging. Those capabilities, combined with the product's lower price, convince me to recommend Ghost Solutions Suite as the better all-around solution. If you plan to use disk imaging as a computer migration strategy, however, check out both products' lists of supported applications before you buy. If you manage a supported brand of blade servers or need to use imaging for Windows Server and Linux, Altiris Deployment Solution for Servers might be worth its higher cost.

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