Optimizing Performance

This section contains the following topics for optimizing file system performance:

• File Compression
• Salvageable Files
• File Purging

File Compression

One way to conserve disk space is to compress files. Use the following information as background for using file compression to optimize system performance:

• NetWare maintains the original version of a file during compression. When compression completes, NetWare replaces the original with the compressed version of the file, provided no errors occurred. If errors do occur during compression, NetWare leaves the original version intact.
• If you have a CD-ROM volume mounted as a volume, treat it as a read-only volume. Do not use file compression on it.
• Compression is a usually a low priority process thread because of compression's impact on performance. If you flag an item for immediate compression during peak system usage, performance may deteriorate.
• You do not need to separate application files from data files to be compressed. You can use the SET command to preclude compression of frequently used applications. For instructions on how to use SET, see SET in the Utilities Reference.
• Monitor compression activity via the SET command's compress screen parameter.
• Backup applications that use Novell Storage Management Services^TM (SMS^TM) back up and restore compressed files. Other applications may decompress them.

Salvageable Files

Salvageable files are files saved by NetWare, after being deleted by users, that can be salvaged (recovered).

Salvageable files are usually stored in the directory they were deleted from. If a user deletes that directory, the salvageable files are saved in a DELETED.SAV directory located in the volume's root directory.

The user can view a list of deleted files in a directory and recover files by using ConsoleOne^TM. For more information on salvaging files, see Salvaging and Purging Deleted Files on NetWare Volumes in the ConsoleOne 1.3 User Guide. Recovered files contain information about who deleted the files and when they were deleted.

Deleted files are saved until the user deliberately purges them or until the NetWare server runs out of disk allocation blocks on the volume.

File Purging

When the NetWare server runs out of blocks, it purges deleted files beginning with the files that were the first deleted. Purged files cannot be salvaged.

Files and directories can also be purged as they are deleted. You can do this one of two ways:

• Use the SET command at the NetWare server to disable the salvageable file feature. For instructions on how to use SET, see SET in the Utilities Reference.You do this by setting the parameter named Immediate Purge of Deleted Files to ON. This increases performance, but at the cost of losing the salvageable file feature. The default for this parameter is OFF (this means that by default, files are salvaged when they are deleted instead of being purged immediately).
• Set the Purge attribute for individual files and directories. When a file is flagged with the Purge attribute, the file is purged when it is deleted.

  When a directory is flagged with the Purge attribute, all files in that directory are purged when the directory is deleted. Such files and directories can't be recovered.

• Use ConsoleOne to manually purge individual files and directories. For instructions, see Salvaging and Purging Deleted Files on NetWare Volumes in the ConsoleOne 1.3 User Guide.