XenData Archive Series software, version 4.5x, has been certified with OS X version 10.5 (Leopard) using the SMB network protocol.  This XenData Technical Note provides configuration requirements when using Mac OS X clients that access an archive running XenData Archive Series version 4.5x.

Introduction

We recommend that Mac OS X clients use the SMB network protocol when archiving to and restoring from a XenData archive. The XenData archive appears to OS X clients as a Windows SMB share. When a Mac file is written to a Windows SMB share (such as a XenData archive), OS X creates a data fork file and a hidden resource fork file. In addition, programs such as Finder write a hidden Desktop Services Store file (.DS_Store file).

The resource fork file is usually small. For example, the resource fork files associated with MOV files created by Final Cut Pro or QuickTime Pro are typically 4KB in size.

The data fork file has the same name as the original and the resource fork file has the same name but is pre-pended with '._'. For example, if QuickTime Pro creates a file called 'abc.mov' and the file is saved to a Windows share, the data fork file will also be named 'abc.mov' and the hidden resource fork file will be named '._abc.mov'.

Configuring a XenData Archive

1. Avoiding the Display of Hidden Directories

Finder will display hidden directories on a Windows share.  XenData Archive Series software stores file system metadata in hidden files contained within hidden directories created at the root of the archive logical drive letter. To avoid displaying these hidden directories with Finder, do not share the archive logical drive at its root.

2. Avoiding Degraded Archive Performance due to Resource Fork and .DS_Store Files

Resource fork and .DS_Store files are frequently accessed. For example, Finder accesses the .DS_Store file and each resource fork file when a folder is viewed. Consequently, these files should be held permanently on the archive disk cache to avoid unnecessary restores from tape. The rules described in this section must be implemented for a 4.5.x version of XenData Archive Series to work properly.

The XenData archive can be easily configured to archive a specific file type to data tape and to also retain those files on disk cache for rapid retrieval by using File Groups.  By creating a File Group on the archive that ensures that .DS_Store files are written only to the magnetic disk cache and not to tape, there will not be unnecessary writing to and reading from the tape archive.

Resource fork files on the other hand should be written to both the magnetic disk cache as well as to tape, allowing a resource fork file to remain with the data fork file.  This is achieved by adding a File Group that selects the resource fork files, saves them to the same Volume Set as the corresponding data fork files and does not have flushing enabled.  This will need to be done for each File Group that flushes files.

Examples of these File Group settings are illustrated below.  Remember that the order of the File Groups is very important.

The Windows Explorer screenshot below shows files that were saved using the File Group settings above and illustrates the data fork files flushed from disk cache and the corresponding hidden resource fork files that are held on disk cache.

3. Avoiding Degraded Archive Performance due to Temporary Files

Configuring a Mac OS X Client: Avoid Degraded Archive Performance due to Icon Preview

When a folder is opened using Finder, all files contained in that folder are read if 'show icon preview' is enabled.  This  will cause unnecessary file restores from the archive.  The best way to avoid this problem is to disable this preview option within Finder.  This setting is found in the Finder menu at View>Show View Options>Show icon preview.

Related Technical Information

• XenData Technical Note XTN1001: Configuring XenData Archive Series Software Version 5.0x for use with OS X Clients

• XenData Technical Note XTN901: Configuring a XenData Archive for Use with Sienna News Automation

• XenData Technical Note XTN902: Using Final Cut Server with a XenData Archive