Check system and upgrade requirements

The max memory parameter must be at least the size indicated in “Pre-installation tasks”.

To verify that your system environment is configured correctly:

Verify that the computer on which you plan to upgrade the Sybase products meets the requirements described in Chapter 2, “Installation Requirements”.
Determine whether your server supports an upgrade to Adaptive Server 12.5.

To determine the release level of your current Adaptive Server (or SQL Server), enter the following command after login in to your server using isql:
```
1> select @@version
```
```
2> go
```
Set the environment variables to the values described in Chapter 4, “Installing Sybase Servers”.
Verify that you unloaded Adaptive Server 12.5 in a different directory than your previous Adaptive Server installation.

If you overwrote your previous server installation:
1. Restore it from your most recent backup.
2. Reinstall the product files for Adaptive Server in a different directory.
3. Continue with the upgrade.
Verify that your operating system is at the proper release level and has all operating system patches needed for Adaptive Server. See the Adaptive Server Enterprise Release Bulletin for your platform.