You can upgrade to Adaptive Server 12.5.x from any of these versions:
11.5.x
11.9.x
For a server installation older than version 11.5.x, Sybase recommends that you upgrade to version 12.0, then upgrade to version 12.5.x.
Only upgrades to and from the same page size are supported. Changing the server schema from a 2K page to nK page size is a database migration. See sybmigrate in the Utility Guide for information about migration.
Upgrading Adaptive Server consists of four processes:
Install the new server either into its own installation directory or on top of the old $SYBASE director.
You must have both the old installation and the new installation to perform an upgrade.
From the new server installation, perform the pre-upgrade checks on the old server using the preupgrade utility.
If necessary, fix any problems that pre-upgrade process reports.
Run the upgrade utility against the old servers to update the underlying schema so that their structures are correct for the new server.
The preupgrade and upgrade utilities are internally called by the sqlupgrade utility.
Each new version of Adaptive Server contains different features that introduce new parameters, commands, reserved words, and so on. For this reason, preupgrade is for preparing the old server for upgrade.
sqlupgrade runs various checks, such as reserved word checks, to determine how much space you must add to the old server to successfully upgrade the old server to the new.
As part of the pre-upgrade tasks, sqlupgrade scans all databases and catalogs and determines how much free space is required to upgrade successfully. Essentially, sqlupgrade searches for the largest catalog, then calculates the required free space by doubling the size of the largest catalog, and adding approximately 10 percent for logging the upgrade changes for each catalog.
During the pre-upgrade process, sqlupgrade returns informational messages as it checks the old server. You must fix all reported problems, and run sqlupgrade cleanly before beginning the upgrade process. Once the old server is eligible for upgrade, sqlupgrade shuts down the old server, starts the new server against the existing databases, and begins the upgrade process.