Blue Coat Systems SGOS 4.x ユーザーズマニュアル

Chapter 1:

Upgrading—Overview

Blue Coat

strongly recommends that you read this document before attempting to upgrade to SGOS

4.x from previous ProxySG operating systems.

Existing features and policies might not perform as with previous versions, and upgrading to this
version might require some additional configuration tuning. This SGOS version provides high
security for the network, so when downgrading to previous versions, not all configurations and
policies are retained.

Changes Between SGOS 3.x and SGOS 4.x

Unlike SGOS 3.x, SGOS 4.x does not permit upgrades from SGOS 2.x or CacheOS 4.x. All systems
must be upgraded to SGOS 3.2.4 before being upgraded to SGOS 4.x. For information on the correct
upgrade path, see Table 2.1, “Upgrade Paths” on page 7.

If you attempt to download the next major release and you receive an error message saying that the
download failed due to policy deprecations, your policy uses constructs that are no longer supported
in SGOS 4.x. You must correct any policy syntax problems before upgrading.For information on
checking on policy deprecation, see "Policy Deprecation" on page 22.

If the upgrade path is followed, most of the current settings on the ProxySG are maintained after the
upgrade. New or transformed settings in SGOS 4.x are taken from the original settings wherever
possible.

About the Document Organization

This document is organized for easy reference, and is divided into the following sections and chapters: