Enterprise Backup Software - 09 May 2000

Data that you store on enterprise networks represents money, and for most organizations, irrecoverable loss of such data would be a financial catastrophe. Thus, choosing the correct backup software is like picking the right vehicle to take your company's receipts to the bank: You want the armored car, not the Yugo. Unfortunately, differences between backup software applications are not as apparent as this analogy suggests. The five enterprise-level backup applications I tested—Computer Associates' (CA's) ARCserveIT Advanced Edition 6.61, Syncsort's Backup Express 2.1, VERITAS Software's NetBackup 3.2, Legato Systems' NetWorker 5.51, and Tivoli Systems' Storage Manager 3.7.1—can deliver network data to storage media. But differences appear in the applications' performance, ease of use, scalability, manageability, and cost.

Defining the Enterprise
For software testing purposes, I defined an enterprise network as a network that has more than 300GB of data to back up within one time window. An enterprise network also has multiple network OSs (although the main backup software runs on a Windows NT 4.0 server) and at least one active mail server. Using this definition, I assembled a test network on which various servers ran NT (one of the NT servers ran Microsoft Exchange Server 5.5), Novell NetWare 5.1 and NetWare 4.11, and Sun Microsystems' Solaris 7. I generated and dispersed several diverse data sets that totaled approximately 350GB in more than 1 million files.

The Test Network
In my test network, the server that hosted the backup software was a Data General AViiON 3704 with four 550MHz Pentium III Xeon processors, 2MB of Level 2 cache, and 4GB of RAM. Disk storage consisted of thirty 18GB 10,000rpm disks in an EMC CLARiiON fibre channel disk array. I configured these disks in five RAID 5 arrays of 66.1GB each. I used one array to store performance-monitor logs and other dynamic data that was not part of the data sets I backed up. For network connectivity, the server hosted two Adaptec ANA-6944B four-port 10/100 Ethernet 32-bit NICs. I used NSI Software's Balance Suite 2.71 for Windows NT to aggregate the eight ports into one IP address for transmit-and-receive load balancing. The tape library's SCSI connectivity relied on dual Adaptec AHA-2944UW Ultra HVD 32-bit adapters.

The robotic tape library was an Advanced Digital Information Corporation (ADIC) Scalar 1000 with four DLT 7000 tape drives and 158 tape slots (for more information about the Scalar 1000, see "Scalar 1000," page 152). I divided the tape drives evenly between the two SCSI adapters in the host server. I loaded the tape library with 29 DLTs and two cleaning cartridges. Between tests, I cleaned the drives.

Service Pack 5 (SP5) ran on all NT servers in the test. The NT servers' drives used NTFS and had less than 2 percent fragmentation.

Three network clients ran on Dell Precision WorkStation 410 systems; each system had dual 550MHz processors, 128MB of RAM, and on-board Adaptec 2940 U2W SCSI host adapters. Each workstation came with a 4GB SCSI disk, and I added three Seagate Cheetah 9GB 10,000rpm hard disks to each system to increase storage capacity. I configured the first system as an NT file server and configured the Cheetahs and system disk as four logical drives. I filled the system with nearly 29GB of data. I set up the second system with NetWare 5.1, configured each physical drive as a separate NetWare volume, and filled the system with 22GB of data. I used the third system for my Exchange server. I used RAID 0 to stripe the three 9GB disks and created a logical drive to hold the 16GB private Information Store (IS) and directory database. I added a 9GB disk to the third system for the 6.5GB public IS.

To create another NT file server, I added a Hewlett-Packard (HP) NetServer E45 that had a 266MHz Pentium II processor, 128MB of RAM, and an Adaptec AHA-2910C SCSI host adapter with three HP 4.2GB 7200rpm disks. I used one disk for the OS and configured the other disks as a RAID 0 stripe set to create an 8GB logical drive. I filled the logical drive almost to capacity with random data.

For the NetWare 4.11 server (Support Pack 8a), I used a Digital PC 3000 with a 300MHz Pentium II processor and 128MB of RAM. In this system, I installed an Adaptec AAA-131U2 PCI RAID controller and attached a Cheetah 9GB 10,000rpm hard disk. On this drive, I created a NetWare volume and loaded it with 7.2GB of data. The Solaris 7 server was a Sun Enterprise 250 server with dual 400MHz 64-bit UltraSPARC processors, 2GB of RAM, and six 9GB 10,000rpm hard disks configured as a RAID 5 volume. I loaded the Solaris 7 server with data totaling 31.5GB.

For the network, I used a 16-port autosensing full-duplex 10/100 switch with 1MB buffers to link the servers to eight aggregated ports on the Data General backup server. All servers communicated at 100Mbps full duplex. Figure 1 illustrates the test network.

Results
Price will be a big factor in your enterprise backup selection. Pricing for enterprise backup products is complex and environment-dependent. Table 1 shows vendor-supplied prices for licensing products on various system configurations. These numbers are for comparison only; contact vendors for detailed price quotes for your environment.

Each enterprise environment has unique complexities and requirements, and a product that is well suited to someone else's environment might not work as well on yours. When you evaluate a product, you need to consider scalability, support, performance, features, ease of use, and cost. Scalability means that a product can grow as your enterprise grows without burdening your IT staff with complex reconfigurations or the need to change backup products altogether. Good vendor support is usually worth much more than any cost savings you might realize at purchase. Differences in the quality of support you receive from vendors can define your downtime, which directly affects your bottom line and your peace of mind.

No product emerged as a strong favorite for enterprise environments. Taking into consideration all the test factors, including scalability and support, I give the overall edge to Backup Express for its excellent performance and midrange pricing. I place NetBackup second for its stability and scalability.

The Test
The products I tested supported a range of autoloaders and advanced features (e.g., the ability to span media and support parallel backup data streams from one client). Each product also offered Storage Area Network (SAN) support. Table 2 compares the products' important enterprise backup features.

I gave the vendors details of the test network and the test procedure and asked the vendors to recommend ways to optimize their products' performance. I tested each product's ability to simultaneously back up 349GB of data on the entire server farm. This test roughly simulated how a 9:00 a.m.-to-5:00 p.m. business would attempt to back up a large volatile data set after hours. To measure performance, I timed the backup job and recorded processor utilization. I then restored 151GB of backed-up data, timed the restore operation, and checked data integrity. Figures 2 and 3, page 138, compare the products' backup and restore performance, respectively.

ARCserveIT Advanced Edition 6.61
ARCserveIT, originally a NetWare and UNIX backup product, supports client agents for Windows 9x, Windows 3.x, NetWare, OS/2, Macintosh, and various UNIX platforms. The product has advanced autoloader support and supports several database agents. CA aims ARCserveIT Advanced Edition 6.61 at companies that use NT as a platform for backup servers. CA designed ARCserveIT to work as a component within the company's Unicenter TNG, a larger enterprise-management product, but ARCserveIT is fully functional as a standalone product. Although ARCserveIT supports features such as centralized backup-database administration, ARCserveIT is a two-tier server and client product and won't scale as readily as some of the other products I tested. ARCserveIT requires NT 3.51 or later, 32MB of RAM, and 40MB to 50MB of disk storage. The product came on a CD-ROM, and a startup guide accompanied it. The CD-ROM included more documentation in Portable Document Format (PDF) files.

I launched the install wizard from the CD-ROM and chose a complete installation. ARCserveIT gave me the option of installing Microsoft SQL Server rather than ARCserveIT's proprietary database, Raima. A CA technical support engineer said the Raima database holds 16 million records (although a patch enables it to contain unlimited records), and installing a SQL database lets you expand beyond 16 million records. By default, the Raima database installed on my test system. After choosing the rest of the defaults, I rebooted the server and ran the device configuration wizard. ARCserveIT identifies SCSI tape drives at the device level and automatically sets configuration parameters. The device configuration wizard recognized the Scalar 1000 and the Scalar 1000's barcode reader. Then, because I had chosen the autoconfigure option, the wizard configured the drives and robot. ARCserveIT let me designate a clean tape slot and set the cleaning interval (clean-tape configuration wasn't this easy in the other products I tested). Finally, ARCserveIT verified the media in the tape library.

ARCserveIT includes a client push agent and uses push technology to improve data-transfer performance between server and clients. After the client receives a backup request, it pushes data across the network in large-packet bursts. The ARCserveIT host server breaks up the large packets and formats them for transfer to the designated storage device. These processes, which improve performance, occur simultaneously between the client and server.

Installing the push agent was easy and quick. In the initial ARCserveIT install wizard, I chose the option to install client agents remotely. The install wizard launched its remote setup executable file (rsetup.exe) and displayed all the Windows clients on my network. I chose the clients on which I wanted to install the agent, provided a domain account and password under which the ARCserveIT agent would run, specified the target directory to install the client files, then clicked OK. The installation process completed in a few minutes. After the initial setup completed, CA notified me that I needed to install SP1 to ARCserveIT. The update process was as simple as the installation was.

ARCserveIT's Exchange Server backup agent uses the Exchange Server's backup and restore API functions to back up an online database. The backup agent can also use Messaging API (MAPI) functions to perform online mailbox-level backup and restore. Although mailbox-level backup and restore is appealing, it doesn't provide disaster recovery or replace full Exchange database backups. The Exchange Server backup agent installed quickly and easily from the server program CD-ROM. On the server, the Exchange Server client appeared with the appropriate Exchange database options in the network client directory tree, which Screen 1 shows.

ARCserveIT's UNIX client installation was fast and uneventful. I mounted the ARCserveIT CD-ROM, then used the pkgadd command to transfer the appropriate Solaris client files to the server. I launched uagentsetup from the server's client directory and accepted the default setup options. Finally, I launched the agent with the uagent start command. On the server, the UNIX client appeared under the client tree hierarchy.

The ARCserveIT client for NetWare uses the NetWare Target Service Agent (TSA) and associated NetWare Loadable Modules (NLMs). ARCserveIT uses a module, nwagent.nlm, to interface with the TSA and process backup and restore operations. To install ARCserveIT on the NetWare servers, I launched a Windows executable file from an NT workstation running the Novell client. The basic installation was uneventful, but to improve the product's performance, CA technical support required that I change several parameters for memory, file, and directory caching and for communications. I also had to download a new TCPIP.nlm module from Novell's Web site to help performance on the NetWare servers.

Before I ran the backup test, I followed CA technical support's performance-tuning suggestions and created a separate device group for each client, which enabled ARCserveIT to use all drives in the library simultaneously. ARCserveIT completed the backup test without a problem, although its backup performance was below average.

When I ran ARCserveIT through the restore test, the NetWare clients performed poorly. I worked with CA technical support to resolve the problem. We discovered the problem wasn't with NetWare but involved the first backup session that ARCserveIT saved to a newly formatted tape. Subsequent restore attempts from that session were extremely slow (5MB per minute). We were unable to isolate the problem's cause, but when we ran individual restore tests, the NetWare client performance was a respectable 170MB per minute. However, because the individual tests didn't include the network and device contention that other products encountered during the usual testing, I estimated ARCserveIT's restore time at 11 hours, 30 minutes.

Setting up and testing ARCserveIT was easy. I didn't need to visit a command-line interface to launch special utilities, nor did I have problems with device recognition and configuration. The administrative GUI was user-friendly and intuitive. Scheduling client and volume management was a breeze. My only complaint with the GUI is that ARCserveIT didn't always seem to leverage all the drives in the autochanger for administrative tasks such as tape formatting and erasing. Thus, I had to format and erase multiple tapes. ARCserveIT's performance was below average, but its low CPU utilization (i.e., 9 percent during backup and 6 percent during restore), easy setup, and low cost would appeal to some organizations.

Backup Express 2.1
Backup Express' three-tiered architecture—which consists of master server, device server, and Backup Express clients—supports Syncsort's claim that the product provides scalability across Windows, UNIX, and NetWare platforms. I tested Backup Express 2.1, which Syncsort released in 1999.

Backup Express' server and client code came on a CD-ROM, and a printed getting-started guide accompanied the code. More documentation existed in PDF files on the CD-ROM. System requirements for running Backup Express on NT include 30MB of disk space for the server and administrative GUI and 64MB of RAM. To install Backup Express, I used Syncsort's Install-by-Phone (IBP) service, which is free to customers evaluating Backup Express. I made an appointment, called a Syncsort support engineer, and proceeded with the installation process on the server.

Installation on the server was wizard-driven and almost trouble-free; the installation seemed to stall after Backup Express' server and client service (CEagent) installed and started. On the Syncsort engineer's advice, I closed the window where the install paused, and the install finished without incident. I rebooted the system, and the Syncsort support engineer told me to use a command-line utility to set up the autoloader. I used install.exe with the q switch to query SCSI devices. The utility recognized the drives and the autochanger. I recorded information that the query generated, then I executed install.exe with the i switch and entered the SCSI device information. The Install program generated a configuration file for setting up the autochanger in the administrative GUI. I launched regedit to make a Registry change that activated barcode support for the Scalar 1000.

I launched Backup Express' administrative GUI to finish the setup process. After I provided an administrator ID and password to log on to the interface, I launched other administrative windows to add the autochanger and the drives and to label the media. The Windows clients were easy to install, but installation required me to visit each server. The setup wizard gives you the option of installing only the client or the client and the administrative GUI. I chose to install only the client and rebooted when I finished the installation. At the server, I used the administrative GUI to create a new node (i.e., client), then I entered the node's name, IP address, and communications protocol. I clicked a scan button to verify communications, and the client installation completed.

I used a similar process to set up the Exchange server. I installed client software as I did on the other NT servers, but I had to provide an Exchange administrator username and password to establish communications with the Exchange server from the Backup Express server. After I connected to the Exchange server, the Exchange node appeared on my node list. The node had the Exchange database hierarchy as a backup option. Setting up the nodes was fairly easy, but installing a large group of nodes could be tedious and time-consuming.

I installed the NetWare clients from an NT machine that ran the Novell client and had a drive mapped to each NetWare server's sys: volume. The installation routine asks you to point to the NetWare server's target directory and installs the client code. You can manually edit the autoexec.ncf file to load the proper NLMs to enable the client. As do the other products I reviewed, Backup Express uses the NetWare TSA and requires you to load the tsands.nlm and tsaxxx.nlm modules before you load cmdllnlm.lib and cmagent.nlm. After these files installed, I confirmed communications and added the NetWare nodes. For the Novell client, I needed to provide a fully qualified username and password to connect to the node. To improve Backup Express' performance and reliability, the Syncsort engineer who guided me through the installation required me to change several memory, file and directory caching, and communications parameters on the NetWare server. I also needed to install the latest tsands.nlm module from Novell Support Pack 8a because the previous version disrupted attempts to back up the Novell Directory Services (NDS) tree on the NetWare 4.11 server.

The UNIX client installed easily. I launched an executable file from the mounted CD-ROM, and Backup Express presented a menu of UNIX clients. I chose Solaris and proceeded with the installation. I returned to the server, verified communications, and used the administrative GUI to install the UNIX client node.

I had mixed feelings working with the third-party interface solution in Backup Express' GUI. The interface was one of the most intuitive among the products that I tested. The screens' layout intelligently presented useful information. For example, the Configure Media window, which Screen 2 shows, presented plentiful and accessible information about tape volumes. However, I found the nonstandard interface quirky and unpredictable. Some windows didn't have size-control buttons or wouldn't respond to conventional Windows actions such as double-clicking the title bar to maximize the size. At times, I couldn't browse to another window until the active window had finished its task.

Backup Express' GUI offers a uniform interface across platforms. For example, the GUI appeared the same whether it ran on my UNIX server or on a Windows platform. This similar appearance can reduce the learning curve for administrators who manage Backup Express on different platforms throughout an enterprise.

I found most of Backup Express' administrative functions, such as scheduling and launching backups and restores, to be straightforward. The Windows and UNIX clients performed well. Twice, however, the Backup Express NetWare client experienced a TCP/IP communications failure and stopped in the middle of a job. The Syncsort engineer and I couldn't find a cause for the occasional communications problem. Restore jobs to all clients went well except for a failure to restore data to disks that were nearly full. A settings change resolved the problem, and Syncsort fixed Backup Express' code to prevent the problem.

Backup Express' backups and restores were faster than those of the other products. Unfortunately, Backup Express also had the highest CPU utilization (49 percent during backup and 31 percent during restore), occupying nearly half of the available processor cycles on my 4X Xeon server during backup. However, if you can afford dedicated backup servers and require high-performance backups, Backup Express might be your choice. The uniform GUI, though quirky, is intuitive. Backup Express is a highly scalable product that can grow with your environment.

The NetBackup server and client software arrived on two CD-ROMs. Eleven manuals accompanied the product. I didn't have to touch the client manuals for Macintosh or OS/2, but I had to read the other nine manuals during setup and testing. From the Data General server's console, I launched NetBackup's install wizard. I chose to install the master server component and accepted the default settings. I also installed Columbia Data Products' bundled Open Transaction Manager (OTM), which provides open-file backup support. The installation wizard recognized the Scalar 1000 from SCSI inquiry information. I used NetBackup's barcode support to inventory tapes in the autochanger.

The NetBackup install wizard recognized the DLT tape drives, though to designate the correct drive number, I had to refer to a drive and slot layout map in one manual's appendix. I found making this designation confusing—and unforgiving if you don't enter the correct parameters the first time. Detailed setup instructions in the 340-page System Administrator's Guide helped me configure the autochanger and drives. NetBackup's print documentation is well written, but information is difficult to find because it's scattered across so many manuals. The online help is easier to navigate but didn't always provide the level of detail I needed. The wizard-based installation functioned reasonably well when I set up my test environment, but complex configurations involving mixed media types or multihosted autochangers require manual setup using media- and device-management utilities in NetBackup's administrative GUI.

Deploying NetBackup's client software for Windows clients was easy. By running the same install wizard that I used to set up the NetBackup server, I remotely deployed the client agents. The wizard provides a remote client installation option and lets you specify a client workstation or search the network. I searched the network and installed the NetBackup client on all the discovered workstations. To initialize the NetBackup service, I had to reboot client machines. The process was fast and trouble-free.

The Exchange client also installed easily. The client runs as an extension of the NetBackup Windows client, uses standard Exchange APIs to back up the Exchange databases, and supports incremental and differential backups that deal only with Exchange transaction logs. For NetBackup to back up the Exchange server, Exchange services must be running.

Installing the UNIX client on my Solaris 7 server also was easy. At the server console, I ran the UNIX client install program from the NetBackup CD-ROM. I then configured a DNS reverse lookup zone for proper name resolution with the NetBackup master server. Remote install options for UNIX clients are available.

NetWare agent installation required considerable effort. Because NetBackup uses only TCP/IP to communicate with NetWare clients, I needed to install and configure TCP/IP for the NetWare 4.11 server. Then, I had to load the appropriate NLMs to enable NetWare's Storage Management Services. These NLMs include the NetWare data requestor and TSAs and were the standard interface for the backup agents of all the products I tested. I also loaded the NetBackup agent NLM (bpcd.nlm). However, the NetBackup agent's latest version wouldn't function on the NetWare 5.1 server. VERITAS technical support suggested that I load a NetWare 3.x version of bpcd.nlm. The only functionality the system would lose if I used the older NLM would be interface capabilities with VERITAS' Backup Exec, a data-backup product. After I loaded bpcd.nlm, my NetWare servers were ready to work with NetBackup.

The NetBackup user interfaces (UIs) took time to learn but were easy to work with; NetBackup dedicates a different GUI to each major administrative function. NetBackup's administrative GUI provides shortcuts to seven administrative utilities, including a report generator, activity and device monitors, and management interfaces for policies, media, and devices. Screen 3 shows the Backup Policy Management interface, which you use to configure policies, schedules, clients, and backup file sets. These elements reside in a NetBackup class. You can create a class to define a group of clients. Then, you can add clients, schedules, and detailed attributes for the backup jobs. The interface wasn't immediately intuitive, but after I worked with it for a couple of days, I became comfortable with the layout logic and the interface's functionality.

NetBackup's backup and restore performance ranks in the middle of the pack. Yet its CPU utilization (10 percent during backup and 4 percent during restore) was among the best of all the products I tested. I worked with VERITAS' technical support staff to adjust data streams and configure multiplexing options. Parallel streaming improved the product's backup performance, but spreading a backup data set across several tapes hurt restore performance because a restore operation requires multiple tape mounts. NetBackup includes a utility you can run manually to consolidate data on one volume and thus improve restore performance.

NetBackup's strengths are its stability, scalability, additional features—which include disaster-recovery storage management—and an extensive list of supported OSs. However, the product's performance was average, and VERITAS needs to improve some interface features. I would have liked easier volume manipulation and clean-tape setup. The installation wasn't as simple as other products I tested, and although the documentation was voluminous, it wasn't well organized. NetBackup also is one of the most expensive products I tested. VERITAS' tier-level pricing matrix multiplies costs according to the number of processors in a server, so expect to pay more if you have SMP servers. You'll also pay $200 each to back up NT desktop clients; Win9x clients are a more reasonable $75 each.

NetWorker 5.51
NetWorker, Legato's flagship enterprise backup application, can run on NT, several variations of UNIX, and NetWare. NetWorker also offers add-on modules for autochanger support, archiving, Hierarchical Storage Management (HSM), and centralized Java-based management. NetWorker has three elements: a server, which maintains the client file index and media database; a storage node, which is a computer that hosts additional attached storage devices; and a client, which is a computer that backs up data to a NetWorker server or storage node. These elements constitute a data zone that is a NetWorker server's responsibility. This modular architecture is flexible and allows scalability across complex networks. According to Legato, a 5.7 release of NetWorker is imminent, but it wasn't available for my test.

NetWorker arrived on five CD-ROMs; one of the CD-ROMs contained all documentation (a paper manual is available for $50). NetWorker Server requires SP3 with 64MB of RAM and 44MB of program-file storage. For online indexes, NetWorker requires disk space equal to 5 percent of the total backup data. Legato certifies NetWorker 5.5 to work with TCP/IP but hasn't certified the product to work with other protocols (e.g., IPX/SPX; those that operate with Microsoft Proxy Client).

When you buy NetWorker, Legato provides enabler codes that you enter after installation to activate the appropriate functionality level. For my test network, I was backing up a sizable chunk of data (225GB) from the local NetWorker server, so Legato gave me enabler codes to activate the NetWorker Power Edition, a NetWorker version that provides better backup performance for environments that have large databases or file systems. You can also buy Power Edition upgrades to support high-speed devices.

NetWorker's installation used a standard wizard interface. From the choices of server, client, update, and uninstall, I installed the server component. The initial installation phase went smoothly; the product asked me only to name the NetWorker server. After rebooting the machine, I launched NetWorker's administrative GUI. Another wizard appeared and guided me through more setup options, such as whether to enable client-initiated backups. I then configured the clients on my test network, gave each client a name, and gave them all membership to the default backup group that NetWorker automatically creates.

To configure the autochanger, I launched the jbconfig.exe command-line utility. The utility recognized the autochanger through standard SCSI inquiry, and a series of prompts led me through drive configuration. The process doesn't forgive syntax errors, and it requires you to know your drives' pathnames as NT understands them. Legato provides other command-line query utilities to help you, but NetWorker's tape-library setup was more difficult than other test products' setup processes.

After I set up the library, I returned to NetWorker's administrative GUI to finish the autochanger's setup and configuration. To let me quickly label all my tapes, NetWorker used all the autochanger drives. Then, I attempted some test backups and found an annoying quirk in the setup process: Jbconfig had by default incorrectly designated one of my drives as 4mm. I didn't initially catch the incorrect designation, so I had problems with incorrect tape labels and backup jobs. I couldn't change the drive configuration through the administrative GUI or from the command line, so I deleted and reconfigured the autochanger. Then, I relabeled the tapes and continued testing.

Installing the Windows clients was easy in my small test environment. On each client, I launched the setup program from the CD-ROM. I chose default settings and named the NetWorker server. NetWorker installs and starts a remote executive service that runs under the system account and allows scheduled backups. Although Legato doesn't provide automated deployment utilities, the company supports using Microsoft Systems Management Server (SMS) 1.2 to deploy NetWorker clients.

The NetWorker client for Exchange Server arrived on the BusinesSuite Module CD-ROM. The install wizard took me through a simple client setup. I also created a custom backup group for the Exchange server and specified a directive (i.e., a command that tells the backup server what to back up) to back up Exchange databases.

UNIX installation was also easy. After mounting the NetWorker CD-ROM, I ran the pkgadd command. Legato provides several scripts for installing the NetWorker server, client, and device drivers. I chose the client option, accepted the default file locations, and designated the NetWorker server on the test network. The only hitch was a loop that caused the install script to run repeatedly. After the install ran twice, I discovered the problem and exited the installation script.

When I attempted to remotely install the NetWare client from an NT box that was running the Novell client, I found a README file in the directory where the Win32 install application was supposed to be. The README file stated that support for remote installation wasn't available and I would need to install from the NetWare server console. I moved to the console, mounted the CD-ROM, and launched the installation program. After I installed the client and its five proprietary NetWorker NLMs, I couldn't communicate with the NetWorker server. After I asked Legato technical support for help, I found that the NetWare client didn't support DNS name resolution. I modified the Hosts file on each NetWare server, but I still couldn't find the NetWorker server with NetWare 4.11. Finally, I downloaded and installed the latest NetWare client (i.e., Netware 4.15) from Legato's Web site. This action resolved the communication problems so that I could perform test backups from my NetWare clients.

NetWorker's administrative GUI was relatively easy to learn, and with some assistance from online documentation, I successfully set up clients and schedules. Administrative tasks in NetWorker revolve around the client. The product assigns policies, schedules, group memberships, and special backup directives at the client level. Screen 4 shows the administrative fields of the test network's Exchange client. Although group membership determines when a client's backup will run, the client schedule determines the backup level (i.e., full or differential).

Legato technical support helped me tune NetWorker for optimal performance. Some of the setting changes increased to 16 from 4 the number of parallel backup data streams that the server will accept. Relative to other tested products, NetWorker's backup performance was above average, but its restore performance ranked low, with the NetWare clients finishing behind their Windows and UNIX counterparts. CPU utilization was respectable (17 percent during backup and 12 percent during restore).

During backup testing, I had trouble with Legato's NetWare clients. When I ran a scheduled backup from the NetWorker server, both NetWare clients dropped communications. Legato technical support told me to launch the backup job from the NetWorker client console on the NetWare server. After I did so, the backup completed with no problems. But requiring that you either use Rconsole to access the server remotely or visit the NetWare server defeats the purpose of centralized administration. The Windows and UNIX clients didn't have any problems.

NetWorker was a solid performer aside from the problems it displayed with NetWare clients. Its initial setup and configuration were somewhat complicated, but the UI was fairly intuitive and easy to navigate. NetWorker is a scalable product that can grow with your enterprise.

Storage Manager 3.7.1
In July 1999, IBM moved ADSTAR Distributed Storage Manager (ADSM), the company's flagship enterprise backup product, to Tivoli, IBM's enterprise systems management division. With that move, ADSM earned a new name: Tivoli Storage Manager. IBM stated that enterprise storage management is a natural extension of enterprise systems management. Storage Manager integrates into Tivoli Enterprise, and you can manage Storage Manager functions through the Enterprise console. However, Tivoli markets Storage Manager as a standalone enterprise backup product that supports a wide range of host and client OSs. Storage Manager Server is available for IBM OSs ranging from OS/2 to OS/400, MVS, and Virtual Machine (VM).

Storage Manager arrived on four CD-ROMs—one each for the Storage Manager server, the desktop clients, the UNIX clients, and the Storage Manager manuals. A thin Quick Start manual accompanied the CD-ROMs. System requirements for Storage Manager are SP4 with 128MB of RAM and 130MB of free disk space. The guide didn't specify client requirements, but I found that the installed client agent occupied only 12MB of disk space and ran on machines that had 64MB of RAM.

Storage Manager uses a wizard-based install. I accepted the defaults for the initial installation and rebooted the system. After you reboot, the Storage Manager Initial Configuration Wizard guides you through the rest of the setup. This wizard is the first of 11 wizards that guide you through the configuration sequence. Even with the wizards' help, Storage Manager's setup was more lengthy and involved than the other test products. Parts of the configuration sequence lend themselves to user errors that cause setup to fail. For example, in the Device Selection Wizard, I found it easy to mistakenly add a drive as standalone rather than attach it to the autochanger. Yet wizards for some other tasks, such as scheduling, were easy to use.

The only other problem I had during the initial configuration was a device conflict that didn't let Storage Manager's server service start. I found that Storage Manager uses a proprietary device driver (i.e., ADSMscsi) to control tape drives and robotic libraries. I needed to disable NT's standard DLT tape-device driver and start Storage Manager's device driver. After I performed those actions, I started the test.

To install the Windows clients, I needed to visit each client node and install the Storage Manager client from the console. The Storage Manager client's components are a backup-and-archive client, a Web client, and a scheduler service. The backup-and-archive client is a standard client GUI for running backups and restores from the client console. You can use the Web client to remotely perform backup, archive, restore, and retrieve operations from any machine or platform that supports a browser. The scheduler service enables scheduled client backups as you define them on the Storage Manager server. The wizard-based setup routine guides you through installation of the backup-and-archive client and Web client, but you need to use Storage Manager's dsmcutil.exe command-line utility to install and configure the scheduler service. IBM said the next Storage Manager release will contain an improved client installation process. Tivoli supports deploying Storage Manager's Windows client with SMS.

I easily installed Tivoli Data Protection for Exchange Server at the Exchange server's console. To improve the Exchange client's performance, I followed the product documentation's instructions to change settings in a client options file. In a production environment, Exchange Server setup is more complicated; you need to configure specific policy requirements and parameters that define how the system handles backed-up Exchange data.

NetWare client installations were straightforward. I copied the Tivoli NLMs to the NetWare sys: directory from the Storage Manager client CD-ROM, loaded the necessary NetWare NLMs to enable NetWare's Storage Management Services, then loaded Tivoli's client NLM (i.e., dsmc.nlm). To enable scheduled client backups from the Storage Manager server, I loaded a client scheduler.

The UNIX client's installation simply required me to run an install script from the UNIX client CD-ROM. The UNIX client includes a client options file (i.e., dsm.opt) for configuring operating parameters. To enhance the UNIX client's performance, I worked with Tivoli technical support to change some parameters. Automatically starting the scheduler process required adding a command to the /etc/inittab file.

During testing, I was unsure which Storage Manager interface to use for certain tasks. The Server Utilities GUI, which resembles a Microsoft Management Console (MMC) snap-in, is a group of wizards that help with Storage Manager Server's setup and configuration. The GUI provides a command-line interface and access to a library of commands that are the power behind the various GUIs and wizards.

Another interface option I explored was the Web administrative client, which impressed me with its functionality and flexibility. When you install Storage Manager, a lightweight HTTP service allows access to the Storage Manager server with a Java 1.1.6-capable browser (e.g., Microsoft Internet Explorer—IE—4.01, Netscape Navigator 4.06 and later) that points to TCP port 1581. Screen 5 shows the Web administrative client interface. The Web administrative client lets you control the Storage Manager server from any PC on your network (including remote dial-up PCs) without installing a special administrative client. Storage Manager on the server controls security.

During the test, Tivoli technical support helped me set performance-tuning parameters and eliminate a crippling timeout problem that arose while I backed up the large data set from the Storage Manager server. Storage Manager uses a diskpool to temporarily store backup data before committing it to tape. The diskpool's size and location have a direct effect on performance. I worked with Tivoli's technical support to create a 9GB diskpool and store it on a relatively inactive RAID 5 volume.

Nevertheless, Storage Manager's performance disappointed me. The product's CPU utilization was on the high side (36 percent during backup and 11 percent during restore), but that utilization didn't translate into fast backups and restores. Tivoli engineers said Storage Manager uses a unique backup database design that performs an initial full backup followed by incremental backups. This "incrementals forever" approach supposedly reduces backup times by eliminating backups of redundant data. Although this strategy eliminates time-consuming full backups, Storage Manager's below-average performance results in incremental backups that are still slower than backups for the other products I tested.

Although Storage Manager has a scalable architecture, it doesn't support important features such as multihosting (i.e., the ability to share a tape library with multiple backup servers). Storage Manager's price is competitive. If Tivoli's base list of supported devices had included the Scalar 1000, the cost of licensing my environment for Storage Manager would have rivaled ARCserveIT's low price. Storage Manager ran backups and restores reliably, but its poor performance overshadowed stronger features such as the Web administrative client and the wide range of supported host platforms.