Technical Notes

Choosing Between Mixed Case File Name Handling and Performance Optimization in Reflection NFS
Technical Note 1270
Last Reviewed 10-Aug-2007
Applies To
Reflection NFS Client version 12.0 or higher
Summary

The Reflection NFS Client gives you two options for handling the case of file names on NFS servers: Optimize for case handling, and Optimize for performance. This technical note explains the two settings and how to change them.

Note the following:

• The Reflection NFS Client standalone product is also included as a component of several Reflection products. For further details, refer to Technical Note 3000.
• For information about which versions of Reflection NFS are supported on each Microsoft Windows platform, see Technical Note 1421.

Windows and UNIX File Name Case Handling

UNIX and Windows handle file name case sensitivity differently, and some Windows applications (some 32-bit and all 16-bit) do not retain the case of file names.

By default, when you use Reflection NFS to access a file, Reflection does extensive internal file name matching to keep track of the case of file names on the NFS server. This functionality does come with some additional overhead, so Reflection also provides options that allow you to optimize this setting for your NFS environment.

Reflection NFS Case Optimization Options

The Reflection NFS Client gives you two options for handling the case of file names on NFS servers: Optimize for case handling, and Optimize for performance.

Read the descriptions below to determine the best configuration choice for case optimization in your environment, and then proceed to Configuring File Name Case Handling in Reflection NFS to verify or change your settings.

Optimize for Case Handling

If you optimize for case handling rather than for performance, Reflection maintains the case of file names. However, to accommodate differences in case handling by Windows and UNIX, Reflection NFS performs file operations such as open, delete, and rename using case-insensitive searching.

An example of the differences in case sensitivity between the two operating systems can be demonstrated by the following scenario. Create a file on your local C: drive called abc.txt, then try to create a second file, in the same directory, called ABC.txt, Windows will tell you that there is already a file by that name. Do the same thing in UNIX (using a host emulator such as Reflection for UNIX and OpenVMS), and you will be able to create the two files. UNIX recognizes abc.txt and ABC.txt as two different files.

To avoid this conflict, make sure that all file names are unique by more than just case. (See the online help for further details regarding this topic and the related Check for Duplicate Names setting.)

If you choose to optimize for mixed case file names, Reflection NFS consumes more memory for storing file name information. This memory usage is temporary, but a UNIX host with many directories and large numbers of files (over 1,000) can cause Reflection NFS to consume several megabytes of RAM at times of heavy use. This can result in slower performance when saving files. This method does, however, provide more secure file protection than optimizing for performance.

Optimize for Performance

If you choose to optimize for performance, Reflection NFS will consume less memory and therefore may perform faster in certain environments. However, this option has several consequences:

• Newly created or saved files will be forced to have all uppercase or all lowercase names (based on your configuration choice).
• Any pre-existing NFS server files that have names that are mixed case or opposite case (from your configuration choice) will not be accessible when browsing or opening files in Windows.
• NFS server files in directories with mixed case or opposite case names will not be accessible when browsing or opening files in Windows.
• Any pre-existing NFS server files that have names that differ only by case may be overwritten by Reflection NFS. (When saving a file, Reflection NFS saves the file to the first occurrence of the name, regardless of case.)

Choosing the Best Option

Generally, the default option (Optimize for case handling) is recommended. This option allows you to have mixed case file names on the NFS server and prevents you from overwriting files with names that differ only by case. You may want to choose Optimize for performance, however, if all of the following conditions are true:

• Performance is a primary concern.
• Your NFS server has many directories and many (over 1,000) files within each directory.
• Retaining the case of new files is not important.
• All existing file names on the NFS file system are either all uppercase or all lowercase.

Configuring File Name Case Handling in Reflection NFS

The setting for file name case handling can be set globally (for all NFS connections) or individually (for each mapped NFS drive). The procedures for each method are presented in the next two sections.

Optimizing All NFS Connections

Follow the steps below to verify or reconfigure file name case handling for all NFS connections in Reflection NFS Client.

1. Access the Reflection NFS Client properties.

2. Click the NFS Files tab, and then click Advanced.
3. Under All Applications, select either Optimize for performance or Optimize for case handling, and then select your preferred case for names on the server.
4. Click OK to dismiss all dialog boxes. You do not need to reboot for the change to take effect.

Optimizing Individual NFS Drives

Follow the steps below to verify or configure file name case handling for individual mapped NFS drives.

1. From either Windows Explorer or My Computer, right-click a mapped NFS drive and select Properties.
2. Click the NFS Files tab, and then click Advanced.
3. Under All Applications, select either Optimize for performance or Optimize for case handling, and then select your preferred case for names on the server.
4. Click OK to dismiss all dialog boxes. You do not need to reboot for the change to take effect.

Related Technical Notes

5008	Technical Notes for Reflection NFS Products