Software Distributor Administration Guide (March 2009)

You can use swcopy to compress files and leave them compressed in a target depot or
compress before network transfer and uncompress afterward.
Precompressing a depot is advantageous when installing or copying to multiple targets.
If the source depot is not already compressed, then each file is recompressed for each
target.
You can set uncompress_files to true to leave a depot uncompressed after copying
with swcopy. For swinstall, the compress_files option will compress all
uncompressed files before network transfer. Files are always uncompressed before
installing them to the target file system.
8.8.1 INDEX and INFO Compression
Another way to reduce your network traffic is by compressing INDEX and INFO files
from the source depot to the target. You can turn on INDEX or INFO compression by
setting the compress_index option to true in the defaults file
(/var/adm/sw/defaults).
The SD-UX controller and target agents will request compressed INDEX files from the
source agent. If the source agent is read only or an older version of SD-UX, the agent
cannot comply; consequently, the client will request a normal INDEX. Otherwise, the
source agent will send a precompressed INDEX and INFO or compress it on the fly.
The target agent will then create a permanent compressed INDEX in the target, depot,
or root. This saves the next request for a compressed INDEX or INFO from having to
compress on the fly.
8.9 Staging
The standard way to install software onto multiple targets is to specify a single source
depot and each target that is to receive the software. However, some software
distribution environments require that you manage software on large numbers of
geographically dispersed target systems. This may require the use of one or more
intermediate source depots or staging areas. This variant on the standard model is
referred to as a staged installation.
There are two reasons for using a staged installation:
1. Minimize the amount of data transferred across a slow and expensive segment of
your network.
2. More easily ensure a successful installation on all targets by reducing the risk of
an unreliable segment in your network.
If your environment has targets organized in separate, local area networks (LAN) and
connected via a low-throughput, less-reliable wide area network (WAN), staging
software to intermediate depots that are local to each grouping of targets and then
doing the installation using these intermediate depots reduces the amount of data that
travels over the WAN segment.
176 Reliability and Performance