CD-Vision 4.0: CD-ROM Users Share and Share Alike
Articles and Tips:
01 Apr 1997
Networking CD-ROM drives in the PC world has not always been easy. Networkinterface boards can be finicky, and the SCSI bus is notorious for hardwareconflicts. Now that CD-ROM drives can be connected via an IDE bus, however,most PCs have built-in CD-ROM drives. Although these drives are convenient,they do not allow multiple users to access the same CD-ROM. Because CD-ROMscan be expensive, many companies are still trying to solve CD-ROM networkaccess issues.
In theory, the easiest way to make CD-ROM information available to multipleusers is to attach a CD-ROM drive to a computer, load networking software,and mount the CD-ROM. Then users simply map a drive letter to the CD-ROMdrive to access the CD-ROM from their workstation. In practice, of course,the process is rarely so straightforward. However, Ornetix TechnologiesLtd. offers a simple, software-based CD-ROM solution: With CD-Vision 4.0,you can attach a SCSI CD-ROM drive to any computer running MS-DOS 5.0 orhigher and create a CD-ROM server that provides IntranetWare/NetWare andWindows NT connectivity.
For this article, I reviewed the CD-Vision 4.0 package, which includesCD-Vision Server and CD-Commander. CD-Vision Server runs on the computerthat is connected to a SCSI CD-ROM drive, creating a CD-ROM server. Userscan access this server from any network workstation running Windows 3.x,Windows 95, Windows NT Workstation 3.51 or 4.0, OS/2, or DOS. No additionalclient software is required.
CD-Commander allows you to install and manage CD-Vision 4.0 servers andCD-ROMs from a workstation running Windows 3.x, Windows 95, or Windows NTWorkstation 3.51 or 4.0. (See Figure 1.) WithCD-Commander, you can dynamically map drive letters to CD-ROM drives. Youcan also use one command procedure to access multiple CD-Vision 4.0 serversand CD-ROMs: You do not have to map a drive letter or use Windows Explorerto search for a CD-ROM drive each time you want to access a CD-ROM.
Figure 1: With CD-Commander, you can manage a CD-Vision 4.0 server from a Windows workstation.
Double-clicking a CD-ROM icon in CD-Commander automatically logs youin to the CD-Vision 4.0 server and launches the appropriate CD-ROM. In addition,you can create custom toolbar folders that contain icons for the CD-ROMsyou frequently access. You can then launch these CD-ROMs without runningCD-Commander.
CD-Vision 4.0 includes two utilities: CD-Vision Console and CD-VisionAdministrator. The CD-Vision Console utility has a C-worthy interface andruns on the CD-Vision 4.0 server. You can use the CD-Vision Console utilityto monitor this server. For example, you can see which users are connectedto the server, how long these users have been connected to the server, whichCD-ROM volumes are in use, and which users are accessing these volumes.You can also clear a user's connection, send users a broadcast message,or shut down the server.
You can use the Windows-based CD-Vision Administrator utility to maintainuser accounts. For example, you can define users and groups and restrictaccess to specific CD-ROM volumes. You can also manage users accessing remoteCD-Vision 4.0 servers, and you can create or edit system login scripts forNetWare 3. (You can also use IntranetWare and NetWare utilities to manageCD-Vision 4.0 servers.)
CD-Vision 4.0 also includes a diagnostics tool, which you can activateduring the installation process. You can use this tool to check for a hardwareor software problem and to pinpoint the cause of the problem so that youcan quickly fix it. This tool is especially helpful if you are using a SCSIconnection.
CD-Vision 4.0 supports both IPX and TCP/IP, allowing you to use nativecommunications protocols such as NetWare Core Protocol (NCP) and ServerMessage Block (SMB) to access the CD-Vision 4.0 server. As a result, theCD-Vision 4.0 server appears as another server on the network. If you havean IntranetWare, NetWare 4, or NetWare 3 network, the CD-Vision 4.0 serveremulates an IntranetWare or NetWare server. If you have a Windows NT 3.51or 4.0 network, the CD-Vision 4.0 server emulates a Windows NT server. Andif you have a mixed environment with an IntranetWare or NetWare server anda Windows NT server, the CD-Vision 4.0 server emulates both types of servers.
In addition, CD-Vision 4.0 offers full integration with Novell DirectoryServices (NDS). The CD-Vision 4.0 server appears as a Server object in theNDS tree, and you can use the NetWare Administrator (NWADMIN) utility togrant access to this server, just as you grant access to any other server.
All CD-ROM drives attached to the CD-Vision 4.0 server appear as networkvolumes, and users can map a drive let-ter to these drives. CD-Vision 4.0automatically mounts the CD-ROM volume when you insert a CD-ROM into a drive;you do not have to manually mount the volume.
Because CD-Vision 4.0 includes a virtual volume feature, you can definemultiple CD-ROM or DOS volumes as one volume. For example, if you had severalCD-ROMs with similar information, such as a reference library on five CD-ROMs,you could group the CD-ROMs as separate directories under the same driveletter. Users could then access multiple CD-ROMs without having to map adrive letter to each CD-ROM drive.
CD-Vision 4.0 also allows you to rename CD-ROM volumes. When you mounta CD-ROM, the name of the CD-ROM becomes its volume name. However, thisname may be cryptic when displayed in a list of network volumes. With CD-Vision4.0, you can assign the CD-ROM volume a more useful name.
CD-Vision 4.0 can even help you improve performance. Because you canattach up to 448 CD-ROM drives to a CD-Vision 4.0 server, you can mountseveral copies of a CD-ROM if multiple users need to access the same CD-ROMconcurrently. CD-Vision 4.0 automatically routes users' workstations tothe CD-ROM drive that can respond first. This load-balancing feature providesoptimal performance, which is especially useful for multimedia applications.
In addition, you can also use CD-Vision 4.0's caching parameters to boostperformance. If users are frequently accessing the same data from a CD-ROM,caching this data to the server's hard drive improves performance. The moredisk space you dedicate to caching, the more data CD-Vision 4.0 can cache.
Ornetix has also taken steps to protect CD-ROMs from theft or damage,so you do not have to worry about leaving them unattended in the CD-ROMdrive: CD-Vision 4.0 prevents users from using the eject button to releaseCD-ROMs from the drive. Only an authorized user can eject CD-ROMs, by usingthe CD-Vision Console utility or CD-Commander. For tighter security, youcan even password protect the CD-Vision 4.0 server.
Finally, you can attach up to 32 magneto-optical (MO) drives or otherdrives, such as an Iomega Jaz drive, to the CD-Vision 4.0 server so thatmultiple users can share these drives as well. For faster access, you canalso copy CD-ROMs to the hard drive of the CD-Vision 4.0 server.
I installed CD-Vision Server on a 486 66 MHz computer with 16 MB of RAMand a CD-ROM drive--typical hardware for companies with older, surplus equipment.The trick was finding a computer that had only MS-DOS 5.0 or higher andwas using the appropriate network drivers. Most computers today have Windows95 drivers, which CD-Vision Server does not detect during the installationprocess.
Before you install CD-Vision Server, you must first load the SHARE.EXEfile for your version of MS-DOS in the AUTOEXEC.BAT file. In addition, youmust load an Advanced SCSI Programming Interface (ASPI) driver in the CONFIG.SYSfile, or CD-Vision Server will not recognize the CD-ROM drive.
If you have an IntranetWare or NetWare network, you must also installNovell's IntranetWare client software or Virtual Loadable Module (VLM) clientsoftware on the computer that will run CD-Vision Server. These clients includeNovell's network drivers.
According to Ornetix, CD-Vision Server does not use redirector software,and in reality, CD-Vision Server does not require another IntranetWare,NetWare, or Windows NT server to run. (For information about redirectorsoftware, see "How Do CD-ROM Networking Products Work?") However, you do need access to other workstations on thenetwork to validate that your connection is up and running.
When you launch the CD-Vision Server installation program, you can selectthe Test CD-ROM Drives option from the main menu to check the SCSI connectionto the CD-ROM drive. (See Figure 2.) As mentionedearlier, this diagnostics tool can detect and pinpoint problems such asa faulty SCSI connection--a common occurrence when drives are daisy chained.
Figure 2: The CD-Vision 4.0 installation program includes a Test CD-ROM Drives option, which allows you to check for hardware or software problems.
After you check your SCSI connection, select the Installation and Setupoption. (See Figure 2.) A window appears, promptingyou to enter the administrator's name, company name, serial number, servername, and default directory. You must enter the administrator's name, theserial number, and a unique server name.
After you enter this information, a dialog box appears, prompting youto choose the Express Setup or Custom Setup option. As you might expect,the Custom Setup option is more difficult to use, requiring you to provideprotocol, volume, caching, and file system polling information. If you choosethe Custom Setup option, however, you can ensure that the network informationfor CD-Vision Server does not conflict with your existing network configuration.
If you choose the Custom Setup option, you should select Protocol Informationfrom the Parameter Information menu. The Protocol Information menu appears,containing two options: Novell NetWare and Microsoft Network. If you selectNovell NetWare, a screen appears, allowing you to define environment settings.For example, you can specify that the IPX protocol is active when you bootthe CD-Vision 4.0 server.
You can also specify an external network number, which identifies thenetwork segment on which the CD-Vision 4.0 server resides. The default numberis zero. If you specify another number, the CD-Vision 4.0 server searchesthe network for this segment number when the server is booted. If the numberyou enter does not correspond to the correct network segment, the CD-VisionConsole utility displays a warning message.
In addition, you can specify an internal network number, which is theunique network number used by the CD-Vision 4.0 server. If you keep thedefault value of zero, CD-Vision Server generates a new number based onthe address of the network interface board installed in the server. Beforeyou change the default value, you should do some research to find a numberthat is not used by another server on the network. If you specify a numberthat is used by another server, that server displays an error message.
You can also specify the number of communications buffers, which determinehow many simultaneous tasks the CD-Vision 4.0 server can perform simultaneously.Because communications buffers affect the server's response to users' requests,you may want to experiment with different values. The maximum number youcan enter is 16.
Because the CD-Vision 4.0 server is a standalone server, it also includesa setting for filtering Service Advertising Protocol (SAP) packets. If youhave a large network and the CD-Vision 4.0 server does not handle logins,you should choose the Filter All Servers option.
Because CD-Vision 4.0 server can respond to Get Nearest Server requestsfrom users' workstations, you can configure a workstation to attach to theCD-Vision 4.0 server when a user boots this workstation. To use this setup,you must first copy the LOGIN.EXE file to the SYS:LOGIN directory on theCD-Vision 4.0 server.
CD-Vision Server also allows you to customize the number of hops, whichdetermines how far the CD-Vision 4.0 server advertises its services. Forexample, if you specified four hops, the CD-Vision 4.0 server would advertiseits services across four segments. You do not need to change the defaultnumber unless network routers reply to Get Nearest Server requests withCD-Vision 4.0 server's address. In this case, workstations on other segmentsmight incorrectly attach to the CD-Vision 4.0 server during their startupprocess.
In addition, you can change the Watchdog Timer parameter, which has adefault setting of Yes. If a workstation does not respond to watchdog packets,the CD-Vision 4.0 server assumes this workstation is no longer connectedto the network and clears the connection.
If you change the Watchdog Timer parameter to No, however, you can reboota workstation that is connected to the CD-Vision 4.0 server, and the connectionwill not be cleared. For example, suppose that a user's workstation hada WAN link to a CD-Vision 4.0 server and the WAN router temporarily preventedthis workstation from responding to watchdog packets. If you changed theWatchdog Timer parameter to No, the connection would not be cleared, andthe user could access the CD-Vision 4.0 server when the WAN link becameavailable. This user would not need to log in to the CD-Vision 4.0 serveragain. You can clear unused connections with the CD-Vision Console utility.
You can also enable CD-Vision 4.0 for NDS by selecting Yes in the NovellNetWare Information form. You must then enter the name of the NDS tree inwhich the CD-Vision 4.0 server will appear, the NDS context, and a usernameand password for NDS tree maintenance.
Finally, you can specify advanced parameters during the CD-Vision 4.0installation process. For example, you can enable File System Polling, whichprompts the CD-Vision 4.0 server to periodically check empty CD-ROM drivesfor new CD-ROMs. You can also set the Maximum Secondary Cache Size to All,which enables the CD-Vision 4.0 server to use as much space on the harddrive as needed.
After I installed CD-Vision Server, I installed CD-Commander on a Windows95 workstation. CD-Commander is not required to access or manage the CD-Vision4.0 server, but CD-Commander offers an intuitive menu and folder systemfor organizing and launching CD-ROMs. For example, you can use the toolbareditor to create a toolbar for frequently accessed CD-ROMs.
If you drag the toolbar into the Windows 95 Startup folder, the toolbarautomatically appears when you access Windows 95. However, I was a littleannoyed because you cannot run the toolbar while CD-Commander is open; youmust exit CD-Commander first.
CD-Vision 4.0 allows you to access CD-ROMs via a dedicated CD-ROM server.Because CD-Vision Server is not hardware specific, you can run this softwareon a 386 or higher computer with a minimum 4 MB of RAM, MS-DOS 5.0 or higher,a network interface board, and a CD-ROM drive. CD-Vision 4.0 supports IntranetWare,NetWare, and Windows NT networks, and more importantly, CD-Vision 4.0 doesnot require proprietary software or terminate-and-stay-resident (TSRs) programson the workstation.
To download a 30-day evaluation copy of CD-Vision 4.0, go to http://www.ornetix.com/ornform.htm. You can purchase a five-user version of CD-Vision 4.0 for U.S. $645, a 10-userversion for U.S. $945, a 100-user version for U.S. $1,245, or an unlimited-userversion for U.S. $1,545. For more information about CD-Vision 4.0, call1-408-383-7050, or visit Ornetix's World-Wide Web site (http://www.ornetix.com).
Steven G. Clegg owns Beacon Strategies, a Fruit Heights, Utah-based firm that specializes in product consulting for the networking andtelecommunications industry. You can reach Steven via e-mail at sgclegg@Beaconstrategies.com.
How Do CD-ROM Networking Products Work?
Both Novell and Microsoft offer CD-ROM server options as part of their core network operating system. Depending on the number of users accessing CD-ROMs, however, configuring your server to provide CD-ROM sharing may affect the server's ability to run other applications. Although setting up CD-ROM sharing on your existing IntranetWare/NetWare or Windows NT server is a cost-effective solution, you should weigh this low cost against the performance hit your users may experience.
Several third-party products, including CD-Vision 4.0, allow you to network a CD-ROM drive. Although each product offers different features for mounting, mapping, and launching CD-ROMs, all of these products fall into one of the following categories:
CD-ROM hardware servers
A client redirector allows multiple users to share a CD-ROM drive that is attached to a workstation. To provide this type of access, you load CD-ROM server software on the workstation with the CD-ROM drive, and you load client redirector software on each workstation that needs access to this drive. When a workstation sends a request to the CD-ROM drive, the client redirector software intercepts the request and sends it to the CD-ROM server (the workstation running the CD-ROM server software). The CD-ROM server answers the request with the appropriate information.
A client redirector is easy to configure, does not use a lot of hardware resources, and allows you to network proprietary CD-ROM drives. However, a client redirector requires proprietary communications software and uses terminate-and-stay resident (TSRs) programs, which may conflict with the BIOS. You must also maintain and upgrade the client redirector software.
A server redirector is similar to a client redirector in one way: You load CD-ROM server software on a computer that is connected to a CD-ROM drive or tower. Unlike a client redirector, however, a server redirector uses an IntranetWare or NetWare server to communicate with workstations on the network.
A server redirector also requires a dedicated CD-ROM server and a NetWare Loadable Module (NLM) on the IntranetWare or NetWare server. Be careful when a vendor claims that its software turns a computer into an IntranetWare or NetWare CD-ROM server. The computer may be a dedicated CD-ROM server, but workstation requests may still be sent through the IntranetWare or NetWare server, using valuable CPU resources. The more users access the CD-ROM server, the more traffic is funneled through the IntranetWare or NetWare server. A server redirector may be a viable solution if your server has plenty of RAM, a fast CPU, and a large hard drive and if users make occasional requests for CD-ROMs.
CD-ROM HARDWARE SERVERS
A CD-ROM hardware server has its own system board, hard drive, network interface board, and CD-ROM drive. As a dedicated network resource, a CD-ROM hardware server does not require any IntranetWare or NetWare server resources and, in theory, can operate without other servers running on the network.
When booted, most CD-ROM hardware servers emulate NetWare Core Protocols (NCPs) by transmitting Service Advertis-ing Protocol (SAP) packets. When IntranetWare and NetWare servers receive these packets, they add the new server to their router tables and then broadcast this information to workstations. A CD-ROM hardware server handles mounting CD-ROM volumes, caching data, and buffering data. When users want to mount a CD-ROM, they simply map a drive letter to the CD-ROM drive.
THE RIGHT SOLUTION FOR YOUR COMPANY
Before you select a CD-ROM networking solution, you should evaluate your network traffic, your company's hardware budget, and the amount of CD-ROM information users require. You should also anticipate your company's future needs. For example, purchasing a client redirector might meet your company's needs today, but you might need a standalone CD-ROM hardware server in the not-so-distant future. You might want to consider installing a CD-ROM hardware server now.
* Originally published in Novell Connection Magazine
The origin of this information may be internal or external to Novell. While Novell makes all reasonable efforts to verify this information, Novell does not make explicit or implied claims to its validity.