It is possible to adjust the CPU settings for a VM, up to one virtual CPU with four cores or 4 virtual CPUs.
It is also possible to adjust RAM, up to the maximum default of 16 gb.
Primary disk space cannot be enlarged, but starting version 2.7.1 external storage can be added:
The default disk space allocated is 8 Gbyte.
Some old appliances which were actually delivered with just 3 Gbyte disk space. In these cases there may be a limitation in the image which may prevent larger amounts of memory and disk space to be defined. If this is the case, increasing RAM and CPU number may not help.
In this case the way to go is to deploy a new machine with the required amount of memory and CPU, create a cluster with the existing appliance so as to get the DB synchronized, or alternatively, restore the database from a backup taken from the primary, license the new PAM with a permanent license and then decommission the old image (making the necessary network changes if applicable)