REVIEWS

Bridging Network Worlds With Server Message Block-Based File Services

To view the Report card.

SCO VisionFS 1.1

We encountered the most significant flaw when we tried to run our Network Computing FileMetric 1.0 benchmark. One portion of our testing involves automatically removing temporary files from several subdirectories from the root directory, where the binaries for the benchmark are located. This simple file-system-level task is accomplished via standard Win32 calls.

When testing SAMBA or when attached to a Novell NetWare or Microsoft Windows NT server, only the files in the correct subdirectory were deleted--as we expected. But when testing VisionFS, files in the child subdirectory as well as all files located in the parent or root directory were deleted. For some reason, VisionFS is unable to correctly interpret the Win32 SMB call made by the Windows95 client. We've sent appropriate C code samples to SCO for analysis. According to SCO, these problems will be addressed in the product's next release.

We found another quirk in VisionFS relating to directory listings. For some reason, the "dir *." DOS command does not function when it's run against a VisionFS share. When we did this, no directories were displayed.

Besides failing to correctly emulate a Windows networking share, VisionFS is not as full-featured as its free counterpart. VisionFS does not support password encryption--passwords and user IDs are passed as clear text across the network from the client to the server. Although this presents a security compromise, remember that other Unix facilities such as FTP or telnet suffer the same lack of security. SCO has indicated that password encryption will be supported once the specifications for Common Internet File System (CIFS) are finalized. For more information about CIFS, see "Surfin' the Web With CIFS" below.

Those needing to follow usage for auditing and resource tracking will be happy to find that VisionFS can be configured to track a variety of events and, via the Windows administrator, one can configure logged events.

This raises an important point that differentiates SAMBA from VisionFS. Although there is an excellent grassroots support system available via the comp.protocols.smb newsgroup, mailing list and consultants, there is no accountability for SAMBA--it's freeware.

While testing, we had several questions regarding SAMBA and got quick responses via the newsgroup. But there is a certain "warm and fuzzy" feeling that many corporate clients experience when phoning technical support when problems or issues arise. This accountability can come at a price, but it is often enough to make some corporate clients go the VisionFS route. From our experience, SAMBA seems to be widely used in academia and in those parts of the corporate community that have strong Uni x backgrounds.

Our version of VisionFS supported only seven versions of Unix but it covered the versions often used in corporate environments, such as Sun Solaris, HP-UX, IBM AIX and, of course, SCO OpenServer. But this list pales in comparison with the more than 20 versions of Unix that SAMBA supports. Although many of these versions are not found in a corporate production environment, several of our editors expressed a fondness for SAMBA since they were able to find compiled versions of SAMBA for some niche version of Unix.

VisionFS has a much better interface than SAMBA. The Windows-based program allows for complete customization of the VisionFS product and one can remotely update or download the VisionFS server. We found that getting VisionFS up and running was a much quicker process than our SAMBA installation. If your SMB resources will be managed by the non-Unix guru or someone who wants an easy-to-use Windows administration utility, VisionFS has a leg up on SAMBA.

Jay Milne can be reached at jmilne@nwc.com.

The Other Route To Unix Resources

One way to accomplish this is to install a Network File System (NFS) client onto each workstation. What does this buy you? Performance is slightly better with NFS than with SMB-based connections. Additionally, with NFS, there is less of a burden on the server because much of the NFS processing is performed on the local workstation. Aside from the quantitative reasons, NFS has a long history with Unix and is often tightly integrated with the operating system. Besides, it's available on a variety of platforms, including Novell NetWare, Microsoft Windows NT, Digital VAX and IBM OS/2.

There are downsides to NFS to consider. If you take the NFS connectivity path, you have to install the NFS client software on each workstation. This can be a time-consuming process and can introduce more problems and additional cost. Clients can cost $75 to $100 each, depending on site licenses.

How We Tested SMB-Based File Sharing

To test performance, we used Network Computing's FileMetric benchmark utility, which performs both reads and writes to the server using two NT clients (3.51 and 4.0) with a Windows95 workstation as the control workstation. We also performed Windows copy commands to transfer files to and from the server. Copy commands were performed four times in succession, Windows NT to NetWare and Windows NT. We dropped the first value and averaged the three remaining times. To measure CPU over-head we used Sun's Perfmeter to sample CPU utilization and the number of packets processed by the server.

To test for compatibility, we installed several applications on the Unix server to be served to each of our clients. These applications included both Windows and DOS applications. We also created directories and files with long file names and tested whether our clients could read those files.

Surfin' The Web With CIFS

CIFS is based on the Windows NT LM 1.2 revision of the SMB protocol and is being championed by Microsoft and other vendors as an Internet version of SMB. But according to several sources, CIFS is merely a later version of SMB that is tightly tied to the Microsoft-centric method of networking and explicitly requires the use of NetBIOS, which is not present in the SMB version 2 specification by The X/Open Co.

So, what does this get you? Well, CIFS allows for clients and servers to share files and other resources using the Internet as your network medium. Using your favorite Web browser or some other application, maybe a Java or ActiveX program, you can access files on a remote computer and actually edit a document and save changes. An alternative being pushed by Sun Microsystems is WebNFS, which is a "lite" version of Network File System (NFS) used by most Unix systems.