Configuring Advanced Features for Traditional Volumes 31
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Minimum Compression Percentage Gain
Enable File Compression
Maximum Concurrent Compressions
Convert Compressed to Uncompressed Option
Decompress Percent Disk Space Free To Allow Commit
Decompress Free Space Warning Interval
Deleted Files Compression Option
Days Untouched Before Compression
4.1.3 Enabling File Compression for a Traditional Volume
You choose to compress files when you create volumes by setting the File Compression
attribute.You can also set the File Compression attribute later. However, after you enable file
compression for a volume, you cannot turn it off. For instructions on setting file compression for
volumes, directories, and files, see “Setting Server-Level File Compression Attributes” on page 30.
The following set command parameters affect how file compression behaves. For information on
how to use the set command, see “SET” in the OES 2: Utilities Reference.
“Days Untouched Before Compression” on page 31
“Minimum Percentage Compression Gain” on page 31
Days Untouched Before Compression
Use the set command’s parameter named Days Untouched Before Compression to set this interval
of inactivity. 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.
Minimum Percentage Compression Gain
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 can be saved by
compression, or if the size difference does not meet the value specified by the set command’s
parameter named Minimum Percentage Compression Gain, the file is not compressed.
4.1.4 Disabling File Compression for a Traditional Volume
File compression is enabled and disabled at the volume level. If you do not enable the File
Compression attribute when you create a volume, you can subsequently enable it using the set
command. However, after it is enabled, 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 more information, see Section 4.1.5, “Suspending File Compression,” on page 32.
