If you have an earlier release of PE already installed, installing PE 3.2 filesets involves a migration installation on top of the earlier filesets. The earlier filesets will be replaced, unnecessary files and directories will be removed and rendered obsolete, and disk space conserved.
There are several files saved as part of the migration installation, in case those files were previously modified. For specific details, refer to How Installing the POE Fileset Alters Your System.
To the ODM and lslpp, however, the earlier filesets will show as installed but marked "OBSOLETE". Additionally, some older directories and installation-related files may remain. In addition, a problem that may result from this is that if you later attempt to remove an older fileset, files from the newer fileset may be removed instead.
To avoid this potential side effect, completely remove older releases of the PE filesets before you begin installation. If your installation currently has ppe.vt or ppe.pedb filesets installed, you should probably remove them because PE 3.2 does not support them. These filesets are not automatically removed or marked obsolete by newer installations of PE, although they should no longer be used with current versions of PE. For more details, see Migration Installation.