ArcInfo, UNIX, and Novell:
Can't We All Just Get Along?
By Thomas J. Siebels, GIS Coordinator
Los Angeles Regional Water Quality Control Board
Information technology (IT) professionals are often dazzled by spectacular presentations of new products and solutions that will make life easier and provide greater functionality. Unfortunately, presentation-inspired wish lists usually bear little resemblance to approved budget requests. Despite the many wonderful options available, most IT professionals are still resigned to playing the hand they are dealt. Such was the case at the Los Angeles Regional Water Quality Control Board (Regional Board) office. The hand its IT staff was dealt consisted of the following:
- ArcInfo 7.2.1 on a UNIX Solaris 2.6 workstation
- ArcView GIS 3.1 on several Windows 98 PCs
- A Novell NetWare 5 LAN
- One full-time network administrator/GIS technician
- About 130 staff members including 30-35 potential ArcView GIS users
The challenge was to allow users to view ArcInfo coverages with ArcView GIS on the desktop. The LAN provided the physical path, but the logical path was a major obstacle. NetWare is not a UNIX-ready network operating system, and the options were few and unattractive. Four possibilities were considered. Each option had serious issues.
- Sharing the UNIX workstation among different users
- Converting the ArcInfo coverages to shapefiles
- Installing a Novell NFS Gateway on the Novell server
- Running a product such as PCNFS
[Editor's Note: Network File System (NFS) is a file system that will mount remote file systems across homogeneous and heterogeneous systems. PCNFS is a generic term referring to all NFS systems running on IBM PC-compatible systems as well as other personal computer systems. The NetWare NFS Gateway transparently integrates NetWare clients into NFS servers allowing DOS and Microsoft Windows users to access files on local and remote NFS servers.]
Evaluating the Choices
Sharing the UNIX workstation was an easily dismissed option. This had been tried before. IT staff found that the average Windows user is quite intimidated at the thought of learning UNIX. Even if Windows users wanted to learn UNIX, there were 30 to 35 potential ArcView GIS users. There was no way one workstation could meet that demand. In addition, the network administrator did not want to add a whole new set of UNIX users to his list of responsibilities. His philosophy was the less access inexperienced users had to the UNIX workstation, the better.
Converting all ArcInfo coverages to shapefiles was equally problematic. A complete conversion would effectively eliminate the power of having ArcInfo at all. Maintaining both shapefiles and coverages would double the workload and disk space needs. In addition, reading shapefiles off the Novell server proved to be quite slow. There was an added issue of file security because the master shapefiles would reside in a shared directory on the Novell server.
Novell NFS Gateway was a more attractive option. It would allow UNIX directories to be mounted to logical drives that could be mapped when logging into the Novell server. This would allow for maintaining one master copy of each coverage. However, the issue of maintaining two sets of user accounts and file system security for the master coverages were major considerations. In addition, the cost of purchasing Novell NFS Gateway would be hard to justify.
PCNFS seemed to be the best option. It would be less expensive than Novell NFS Gateway but still allow UNIX directories to be mounted on logical drives. However, there were still the issues of maintaining two sets of user accounts and file system security for the master coverages. Testing showed that trying to get the PC network cards to run PCNFS and NetWare simultaneously was difficult.
ArcSDE Provides the Solution
During this discouraging process, the Regional Board received an evaluation copy of ArcSDE for Coverages. After a couple of phone calls to Esri, the decision was made to try it. The solution was reached in a couple of days.
ArcSDE was very simple to install and administer. Registering coverages proved equally easy. Novell was no longer an issue because ArcSDE runs on pure TCP/IP. Users do not even have to log in to Novell to access the coverages. Now staff were able to view ArcInfo coverages right off the UNIX workstation without logging into either UNIX or Novell. Since the ArcSDE layers are read-only by default, file system security was not an issue. This solution alleviated virtually all of the system administration headaches.
The real test was getting the staff to try it. It caught on quickly. IT staff built a few ArcView GIS projects for each unit with commonly referenced layers already in place. Other layers could be brought in by adding more database themes.
Suddenly ArcView GIS was the hottest tool in the office. Instead of overwhelming one ArcInfo specialist with requests for maps, people began generating their own products. They were still able to save the projects locally and customize them as needed. Also, they could still add their own local data. Performance was drastically improved as well. One street network, which took two minutes and 14 seconds to draw as a shapefile on the Novell server, took only 22 seconds to draw as an ArcSDE for Coverages layer.
ArcSDE for Coverages meant real GIS to the Regional Board office. It does, however, have a few drawbacks. The tables have limited functionality, and there is no geocoding capability from an ArcSDE for Coverages layer. Staff work around that by converting the layers to shapefiles when more utility is needed.
This has proved to be a blessing in disguise. Staff have been able to convert the layers to shapefiles, make corrections, and e-mail the revised shapefiles back to the administrator. The administrator then replaces the layer with the corrected version so all staff will see the changes. This was tested by having a PC display a layer in ArcView GIS. The administrator changed the geometry in the original ArcInfo coverage. By simply clicking the theme off and on, the changes were reflected back on the PC. The same held true for attribute changes.
Since ArcSDE for Coverages was included with ArcInfo 8, the Regional Board is now in full production. This has proved to be an easily implemented, cost-effective solution. It is also a great interim solution for eventual conversion to database-driven GIS with ArcSDE.
For more information, contact
Thomas J. Siebels, GIS Coordinator
Los Angeles Regional Water Quality Control Board
320 W. 4th Street, Suite 200
Los Angeles, California 90013