Running a script inside the guest OS,?

Question

Virtualization

Greetings.
I need to do the following thing. Our product will be delivered in different modifications. Mods differ from each other, including the size of the virtual disk space.
Introductory:
1. The administrator deploys our product from a virtual appliance.
2. Raises the VM.
3. Changes the size of the virtual disk in accordance with the selected modification.
4. In response to a disk size change inside the guest OS, some script (or set of scripts) should run to configure the rest of the system settings.
Task:
All components are already available: virtual appliance, scripts, etc.
It is not clear how to run this script when changing the size of the disk space or on another trigger?
Much in advance.

Answer 1

I misunderstood a little, but the algorithm is as follows:
create a file, write the current space size to it.
The task scheduler (cron) once an hour (minute/week/month) runs a script that compares the current space size with the one written to the file. if different, it writes a new size and performs the necessary actions.
what is the problem?

Answer 2

S1ashka:
Thank you. Interesting advice. Might work as a temporary solution.
Still, I need to find a way to respond to events produced with the VM at the management level. I've seen somewhere that this functionality is implemented in VMWare tools, but, for the life of me, I can't find where. Well, let's look :)
Xenon:
Thanks for the tip. By the way, in our case, the change in the size of the disk space occurs on a running machine.