Due to the unnecessarily greedy nature of SCCM if when you create a package distribution point there is more than one drive available to the server it will always opt for the drive with most space.
Our server has 3 drives:
C:\ = 50GB System Drive (for OS etc)
D:\ = 200GB Data Drive (for package storage etc)
P:\ = 50GB Page File (it's an old VM)
It got to the point where our data drive got to 151GB capacity (49GB free) and discovered that the P:\ drive actually had 50GB available.... So it helped its self and created an SMSPKGP$ folder and proceeded to fill it up.
Then when P:\ got to 10GB free it realsied that C:\ had about 40GB free and proceeded to create a SMSPKG$ folder and so on and so forth.
This only became apparent to me after it had been utilising this space for a while so I discovered a nice little easter egg that isn't widely publicised by M$.
If there are drives on your SCCM server you don't want it to use simply create a file on the root of the drive named
NO_SMS_ON_DRIVE.SMS
I've seen various versions of this listed on different sites such as "nosmsondrive.sms"; let me tell you now - this doesn't work (or didn't for me).
I know now that the correct syntax is NO_SMS_ON_DRIVE.SMS as I had a "Install retrying" notice on an AppV package DP install and it stuck until I deleted this file.
Hope this can help someone else one day...
C