Question about VDS memory?

Question

System administration

There is a dedicated server with a total memory of 500 gigs.
Created 8 vps, each with 50 GB of memory and each of them has 25 GB occupied. On VDS there are 100 gigs not distributed.
Admins say that when free memory decreases, VPS also decreases for VDS,
that is, VPSs are stored as images on VDS and now occupy 200 GB of memory.
Is it so? or immediately when creating a VPS, it is marked as occupied by 50 gigs, and the fact that 100 gigs remains in the future will not decrease noticeably when the memory of the VPS decreases?

Answer 1

It depends on what type of images for the vps disk space were created, there are 2 of them - one immediately occupies all the allocated space, the other expands as it fills up. One way or another, you won’t get out of the volume limit (without taking into account the overhead from the image format), only if you cut vps snapshots.
You most likely have expanding images.