Setting Server-Level File Compression Attributes - Novell Open Enterprise Server 2 System Administration Manual

Only Inactive Files Are Candidates for Compression
Files automatically pass in and out of their compressed state as they are unused, then used. It is not
necessary to separate application files from data files for file compression because NetWare
compresses files based on the interval of time that a file remains inactive. Most application files are
used regularly.
Use the set command to preclude compression of frequently used applications. For instructions,
see "SET" in the
Decompression Activity Depends on Available Space
Compressed files are uncompressed as they are needed, then remain uncompressed until they are
inactive for an extended period. For a file to be uncompressed, there must be enough free space on
the volume to accommodate the uncompressed file size.
Immediate Compression Impacts CPU Performance
Compression is 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
might deteriorate.
Files Remain Compressed during Backup and Restore
Backup applications that use Novell Storage Management Services
restore files in their compressed state. Other applications might decompress them.
Compressed Volumes Remain Compressed
The File Compression attribute can be turned on when you create the Traditional volume or at any
time afterwards. However, after you enable file compression for a Traditional volume, you cannot
turn it off. Instead, you can suspend the compression activity, as needed.
If you want to turn off file compression, you must back up the volume in its uncompressed state,
then restore the data to a new volume on which the File Compression attribute is not set.
How to Monitor Compression Activity
Monitor compression activity via the set command's Compress Screen parameter. For instructions
on how to use the set command, see "SET" in the

4.1.2 Setting Server-Level File Compression Attributes

For the NetWare server, the compression parameters apply to all files and directories in
compression-enabled volumes on the server. They have no affect on the file compression for
volumes where the volume's File Compression attribute is disabled.
The following list identifies set command parameters that affect file compression. For details
about each parameter and instructions for setting them, see
in the
30 OES 2: NetWare Traditional File System Administration Guide
OES 2: Utilities
OES 2: NSS File System Administration
Compression Daily Check Stop Hour
Compression Daily Check Starting Hour
Reference.
OES 2: Utilities
Guide.
(SMS ) can back up and
TM TM
Reference.
"Configuring Compression for a Server"