In the virtual server environment, it is very easy to adjust the server's memory in order to better suit your requirements and more efficiently use the server hardware.  However, it is important for you to be aware that the PSQL 11 engine license can break if you change the size of the server memory.  In fact, the PSQL 11 engine license can break if any of the following changes occur to the server configuration: 

(1) Server memory size change.
(2) Number of CPU, or the type of CPU change.
(3) Mother board change.
(4) Disk serial number change (this can an issue when your hot swappable RAID drives fail).
(5) The server name is change. 

As you can see, Pervasive implements strict rules to protect their PSQL engine from being copied, and this can be easily done in a virtual environment.  For that reason, we typically suggest that our customers reserve a server with enough memory for future growth so they can avoid changing the memory size down the road when their database grows or some additional task is added to that server. When the PSQL license breaks, fixing it creates an extra burden. So the typical practices involved in dynamically adjusting virtual server memory size or number of CPUs do not work very well with PSQL due to their copy protection scheme. 

If you have to adjust the server hardware configuration (i.e. memory), then it is suggested that you un-register your PSQL 11 engine from your server first.  Then make your adjustment.  Once the server hardware configuration changes are done, register the same key again.

Because Pervasive recognizes these rules are strict, so in PSQL 12 & after, they have dramatically reduced the license checking.  For PSQL 12 and after, as long as you don't change the server name (the NETBIOS name), then the registered license key will not break.  Because of the relaxing of licensing control, PSQL 12 & after is much suitable to install on virtual server and cloud computing environment. 

EMK