Air Cleaner User Manual

sbcomp and sbuncomp
Purpose
Compresses and decompresses data respectively.
Syntax
 sbcomp 
 sbuncomp 
Description
The sbcomp command compresses data from standard input and sends the
resulting compressed data to standard output. The sbuncomp command
uncompresses data from standard input and sends the resulting decompressed
data to standard output.
The sbcomp and sbuncomp commands are used as filters and use only memory to
perform the compression or decompression (there is no intermediate file storage
used). Performing software compression and decompression uses a great deal of
CPU resource and can affect the overall performance of the system. If the data is to
be written to a hardware device that performs its own compression, do not
compress the data before writing to the media, as this uses CPU resources
unnecessarily.
If you select to compress data before writing to media when performing any
SysBack backup command with the -p flag, the resulting backup data is piped
through the sbcomp command before sending it to the sbwrite program, which
places the data on the output media. The SysBack restore commands always read
the backup header to determine if the data on the backup was compressed using
sbcomp, and then pipe the data output by sbread to the sbuncomp program
before the data is restored to disk.
Flags
None.
Examples
1. To compress data in the file /data and send the results to sbwrite to write to
the tape drive /dev/rmt0, type:
cat /data | sbcomp | sbwrite -Svp -tl -nrawlv /dev/rmt0
2. To decompress and restore the file /data from the backup performed above,
type:
sbread -Sv /dev/rmt0 | sbuncomp > /data
Related Information
The sbread and sbwrite commands.
A-62 IBM Tivoli Storage Manager for System Backup and Recovery: Installation and User’s Guide