Even if you want to put things in seperate partitions, i am constantly beating up other IT Guys with the simple fact of, You do not create a root or c: drive with a tiny amount of space for the base OS with the assumption everything else will go to a different drive/partition, Always overspec the root/C: drive beyond what you expect for updates/patches/future. I see too many servers with root/c: drives totally full because some bonehead set them up with 5 GB, 10 GB and assigned all the rest of the space to a second map/drive letter without taking into any account, the growth from updates, swap usage, future changes, etc.
We thin provision all of our virtual linux 3CX servers with no less than 50 GB such that there is also a decent space for recordings and backups, and if we start to run that limit, we add space, or add a new virtual disk with say 100-200gb and set backups and recordings to there, and flush them out of the main partition.
Wasteful as it may seem, we set the windows boxes to thin provision of 100-200 GB as the newer versions of windows server love to pile on windows updates like a trash pile into the winsxs folder and fill up disks needlessly, and even the dism tool will not clean it out to any respectable level, windows update is a wasteful dumpster fire.
