dltptf has a few nice features with it, on V7R1 and V7r2 if you have on  the ptf related to such.

You can go and remove the savf files in qgpl on those that are permanently applied (or superceded) and you can also go and delete those that are coveronly and those that are on order only, which if you use the java interface and suck down, once in a while you will get one that fully does not come down and it is marked as coveronly.

https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/IBM%20i%20Technology%20Updates/page/Delete%20PTF%20%28DLTPTF%29%20command%20PTF%20selection%20criteria

is the link to the page and has the ptf which you can actually do an immediate apply of just that ptf so the command works. I had several gb (like 5 or 6) of perm applied stuff. I know, these days 5 or 6 gb is nothing compared to the days of old when we talked mb, but it does add up when you copy, etc.

chris