I have seen that to increase disk space on a VMWare management VM (ESXi on premises). You need to follow a specific article (sk94671) to add a disk and bring it into the vg_splat LVM Volume Group and then use lvm_manager utility to increase the lv_current partition.
The VM has enough unallocated space in vg_splat to just expand lv_current though using article sk95566 and lvm_manager only. It would appear I can just skip adding a disk to the VM in VMWare and just expand lv_current using lvm_manager. There is 16 GB of unallocated space in vg_splat so my plan was to add 5 GB to lv_current which would then end up using 10GB total since another 5GB would also need to be reserved for upgrades.
I wanted to make sure there wasn't something with adding a disk that is necessary under VMWare VM when only increasing lv_current with lvm_manager that I would be missing if I just used article sk95566. None of the commands before lvm_manager in sk94671 would seem to indicate adding a disk is necessary if you have enough unallocated space in vg_splat to expand it, but I just wanted to make sure I wasn't missing something that gets done behind the scenes that wouldn't be done with following (sk# EDIT correction) )sk95566 that just uses lvm_manager.
Also is there a certain amount of unallocated space that must be available outside of the 'upgrade reserved'? I could not find any info that says so. Surely lvm_manager would warn me if so I think. There would be about 4GB unallocatted space after the change. Since it is a VM, Gaia snapshots are not used.