A very easy and fast way to identify which virtual machines of a Hyper-V host have dynamic memory enabled. Of course, with the help of PowerShell.
To check if a particular virtual machine uses dynamic memory, type:
Get-VMMemory -VMName DC01
where DC01 type the hostname of VM. You will see the information in the DynamicMemoryEnabled column that will be True or False, as the case may be.
To check which virtual machines of a Hyper-V host use Dynamic Memory, type:
Get-VM | Get-VMMemory
Again, in the DynamicMemoryEnabled column, you will get the information.
More about the Get-VMMemory cmdlet.