1.114: How can I recover space after installing updates?

Note: If you are a /usr server, do not use this because the files
      mentioned below are needed by /usr clients and cannot be deleted.

Installp creates numerous files in /usr to clean up after
failed/rejected installs and also for de-installing uncommitted lpps. 
Once you have COMMITted packages you can remove these files safely. 
Depending on your installation activity the numbers can be significant:
hundreds-to-thousands of files, megabytes of data.

Files eligible for removal are associated with each "product" you have
installed; the largest collection being due to bos. After
COMMITting bos lpps, you may safely remove all files of the form:

              /usr/lpp/bos/deinstl*
              /usr/lpp/bos/inst_U4*
              /usr/lpp/bosadt/deinstl*
        and   /usr/lpp/bosadt/inst_U4*

You may repeat this for all additional COMMITted products (e.g.,
bostext1, bosnet, xlc) you have on your system.

This problem of lingering install files is a known defect in installp. 
If you have installed PTF U411711 (or any superseder of it: U412397,
U413366, U413425) the deadwood in /usr will not be quite as prevalent. 
No single PTF currently available completely corrects this problem.

On my own 320, the following freed up 12.4M in /usr:

       # rm -R /usr/lpp/bos/deinstl*
       # rm -R /usr/lpp/bos/inst_U4*