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You can conserve disk space by compressing files. You choose to compress files when you create volumes. However, once you enable file compression for a volume, you cannot turn it off. For more information on file compression, see File Compression.
IMPORTANT: Do not use file compression on a CD-ROM volume.
You do not need to separate applications from data for file compression. This is unnecessary because the SET parameter named Days Untouched Before Compression can eliminate the compression of applications that are used regularly. This parameter specifies the number of days that must pass without access to a file before the file can be compressed. The parameter uses the date the file was last accessed to gauge whether a file should be compressed.
To avoid the overhead of uncompressing files that do not compress well, the system calculates the compressed size of a file before actually compressing it. If no disk space will be saved by compression, or if the size difference does not meet the value specified by the SET parameter named Minimum Percentage Compression Gain, the file is not compressed. For a general description of the SET command, see SET in Utilities Reference.
For a file to be uncompressed, there must be enough free space on the volume to accommodate the uncompressed file size.
For instructions on setting file compression for volumes, directories, and files, see Setting File Compression Attributes.
For instructions on enabling or file compression, see Creating a Traditional Volume in the Novell Storage Services Administration Guide.
File compression is enabled and disabled at the volume level.
If you do not enable file compression when you create a volume, you can subsequently enable it using the SET utility. Once enabled, however, file compression cannot be disabled on the volume unless you re-create the volume.
You can temporarily suspend file compression using the SET command's Enable File Compression parameter. For a general description of the SET command, see SET in Utilities Reference.
To set file compression attributes for a volume (including enabling compression), use SET for instructions on using SET for the file compression attributes, see Using SET to Set File Compression Attributes for Volumes.
Use SET to set file compression attributes for an entire volume. File compression SET parameters do not affect the volumes file compression is disabled on.
IMPORTANT: Do not use file compression on a CD-ROM volume.
To change SET parameters, execute the SET command at the server console prompt.
The following list identifies SET command parameters that affect file compression. The settings apply to all files and directories in compression-enabled volumes on the server. For the function and range of values associated with each SET parameter, see SET in Utilities Reference.
Use SET command's Enable File Compression parameter to temporarily suspend file compression for a volume. For instructions on using SET to suspend file compression, see SET in Utilities Reference.
You can also use the MONITOR command to change file compression parameters. For a general description of MONITOR, see MONITOR in the Utilities Reference.
While file compression is suspended, files that would have been compressed are queued and compressed when compression is re-enabled.
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