AIX Tip of the Week

Backing Out AIX Updates

Audience: AIX Administrators

Date: November 19, 1999

According to the Wall Street Journal, several recent well publicized web outages were caused by inadequate software change control. Several useful change control features are provided in base AIX. One particularly useful function is the ability to back out software updates.

The ability to backout updates requires that they be installed using non-default settings. On the smit install_latest screen, change two of the options as follows:

Commit software updates? No
Saved replaced files? Yes

These settings will save the replaced files when the updates are applied. At some future point, you can either commit the updates (smit commit), or back them out (smit reject). The backout automatically restores the original files.

** Recommendation: To be safe, always make a system backup (mksysb) before applying updates.