I'm using Dynamic Memory for all my VM's and tend to start low (512MB). However, it happend to me that some software did not install as there was not enough memory assigned.
Until now, i had to shutdown the VM, adjust the startup, and started the VM again to install the software, but ....
I just discovered a way to raise the Assigned Memory on demand, by increasing the Memory buffer value. This is configurable during runtime with a value up to 2000% !! So use with care, as the change is immediate
This percentage is used to assign extra memory based on the current Memory Demand. So if your current demand is 450MB a 100% Buffer will give you an assignment on ca. 900MB if the host has enough memory available.
You may change this value back afterwards, but the memory may not be immediateyl removed from the VM, unless the host does not require it elsewhere.