zasran​

This could be easily tested by creating a test pool with fixed=1 and then increase it to 2

I've just did a quick test on our environment changing from 2 to 3 and the existing VM's were retained, but new VM's were created as 001, not as 100! Keep that in mind.

What's the reason that keeping the current names is so important? Eventually they'll disappear after they have been deleted or recomposed (I guess) and will be replaced by 3 digits.