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Troubleshooting File or Directory Access Problems with Reflection NFS
Technical Note 1146
Last Reviewed 07-Jul-2005
Applies To
Reflection NFS Client version 10.0 or higher
Summary
Technical Note 1146
Last Reviewed 07-Jul-2005
Applies To
Reflection NFS Client version 10.0 or higher
Summary
This technical note explains how to troubleshoot problems accessing NFS server file using the Reflection NFS Client.
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 1866.
Troubleshooting NFS File Access Issues
NFS file access problems are typically one of three types:
- Inaccessible files: files you can't see, open, edit, save, move, or delete
- Garbled file names
- Corrupted or damaged files
The sections below provide troubleshooting tips for each type of problem.
Note: Some of the tips in this technical note direct you to make changes to Reflection NFS client settings. It is important to note that settings changes can be made either globally in the Reflection NFS Client Properties, or individually in the Properties of each NFS mapped drive. Global changes affect all non-mapped NFS connections and are used as the default for newly mapped NFS drives. To access the global settings, you must be a member of the Windows administrators group.
Resolving File Inaccessibility Issues
Successful NFS file access depends on many factors. Files may be inaccessible due to file or directory permissions, ownership issues, drive-mapping problems, caching conflicts, or network activity.
Permissions and Ownership Issues
For a detailed discussion of NFS file, directory, and exports permissions issues, see Technical Note 1178.
Drive-Mapping Problems
For a detailed discussion of Reflection NFS drive-mapping problems, see Technical Note 1050.
Caching Conflicts
If file or directory caching is enabled, you may be unable to see files or directories. Try disabling the NFS client's caching features, manually refreshing the directory, or changing the NFS client's directory refresh setting.
Network Activity: Read, Write, and Directory Buffers
By default, the NFS client configures buffer settings dynamically. However, if your network is busy or erratic in its response time, automatic configuration may not behave as expected.
Use the NFS Statistics feature in the NFS Utility to view your NFS network statistics. See the "Using NFS Statistics" section below for details on what statistics to look for. If indicated, you may want to manually lower the NFS client's Read, Write, and Directory buffer sizes, or configure NFS to use TCP.
Try reducing the buffer sizes to 2048. If this improves performance, try increasing the buffer settings by increments of 1024 until you find the setting that best suits your network environment.
You also have the option of changing the transport type to TCP. TCP provides more error checking and better retransmission, but also has more overhead than UDP. If you select TCP, you must restart your PC for the change to take effect.
Depending on your network environment, one or the other of these options may work better for you.
Nlockmgr Daemon
Nlockmgr is an NFS server daemon that enables file locking and sharing. However, it is not supported by all hosts. If this daemon is not available on your host, enable it or disable file locking and file sharing in the Reflection NFS client. If you want your users to be able to share files, you need the nlockmgr daemon to prevent file corruption.
For more information on running NFS server daemons, see Technical Note 1100.
Resolving File Name Issues
Several factors affect the appearance of NFS file names: client settings, host settings, and case sensitivity.
NFS Client Settings
The configuration for the NFS client's NFS File settings are configured determines how you will view and save files on your NFS host. These settings can be confusing and are version-specific. Please refer to the Name Mapping topics in the Reflection System Administrator Guide or the NFS client online help for details.
Host Settings
For problems on VMS hosts with tilde (~), underscore (_), and dollar sign ($) symbols, refer to the VMS information in your Reflection System Administrator Guide or the NFS client online help.
Case Sensitivity in Windows
Microsoft's Windows operating systems display file and folder names with only the first letter capitalized in Windows Explorer, on the desktop, and in Windows programs. This means that you may see NFS file names displayed with the incorrect case. This is an operating system design issue.
See Technical Note 1270 for help with handling mixed case file names in Reflection NFS.
Resolving File Corruption Issues
NFS does not change the content of a file unless you specifically run the file through a DOS/UNIX or UNIX/DOS conversion utility. Changes to the content of a file (modifications or corruption) can be caused by either the transfer process or host configuration. To troubleshoot file corruption, follow the suggestions listed below.
Nlockmgr Daemon
See the Nlockmgr Daemon tip in the Resolving File Inaccessibility Issues section above.
VMS File Access Settings
To avoid file corruption and access problems on a VMS or OpenVMS host, you must enable VMS/OpenVMS in the Reflection NFS Client. Follow the steps below.
- To change the VMS settings for a mapped NFS drive, right-click the drive, and then click Properties on the shortcut menu.
- On the NFS Files tab, click the Advanced button.
- In the NFS Directory and File Names dialog box, select VMS/OpenVMS host and click OK.
- A dialog box will prompt you with information about the settings changes that the NFS client will make automatically. Click OK.
For more details, consult your Reflection System Administrator Guide or the NFS client online help.
File Caching
Try disabling File Caching. For details, consult your Reflection System Administrator Guide or the NFS client online help.
Read, Write, and Directory Buffers or TCP
See the Network Activity: Read, Write, and Directory Buffers and TCP tip in the Resolving File Inaccessibility Issues section above.
NFS Server Daemon Versions
Reflection NFS may experience difficulties with certain server daemon versions. By default, the NFS client uses NFS daemon version 3 and only switches to version 2 if version 3 is not present. Try configuring the NFS client to use version 2 by default. See your Reflection System Administrator Guide or the NFS client online help for details.
End of Line Characters
DOS and UNIX use two different End of Line (EOL) indicators. UNIX uses a carriage return (CR) while DOS uses a combined carriage return and line feed (CRLF). If you create a file with a UNIX text editor, the EOL character will be a CR. If you create a file with a Windows editor, the EOL will be a CRLF.
This difference will cause a UNIX file to display incorrectly in a DOS environment and vice versa. The file may appear as one long line of text with no carriage return at all, or it may contain black boxes at the end of each line.
Files can be shared and edited both via DOS and UNIX as long as you convert the EOL characters before you edit the file. If you don't convert the EOL characters first, you may corrupt the file. See your Reflection System Administrator Guide or the NFS client online help for details.
NFS Utility Statistics
You can check NFS statistics using the NFS Utility available in the Reflection Utilities program group. If you are experiencing file corruption issues, check the statistics listed below.
- Network Errors: the number of network transactions that could not be completed. This number should be very low (approximately 0-3). A higher number here typically indicates network traffic problems or slowed response times.
- RPC Discarded Replies: the number of remote procedure call (RPC) requests that have expired without reply.
- RPC Timeouts: the number of remote procedure call (RPC) reply packets received after the timeout limit. The RPC Discarded Replies should not exceed the RPC Timeouts by more than 30 to 40 percent.
To resolve issues related to these NFS statistics, try reducing the Read, Write, and Directory buffer sizes to 2048. If this improves performance, try increasing the buffer settings by increments of 1024 until you find the setting that best suits your network environment.
You also have the option of changing the transport type to TCP. TCP provides more error checking and better retransmission, but also has more over-head than UDP. If you select TCP, you must restart your PC for the change to take effect.
Depending on your network environment, one or the other of these options may work better for you.
