I was moving a customers VM’s from their site via vMotion into our datacenter, and one of the problems you can run into is with reservations and limits. There may have been valid reasons for having limit and reservations, but they can also be the root of performance problems. As this was not the case with this customer, I created the one liner below in order to remove the reservation and limits.
Get-Cluster ClusterName | Get-VM | Get-VMResourceConfiguration | Set-VMResourceConfiguration -CpuLimitMhz $null -CpuReservationMhz 0 -CpuSharesLevel
"Normal" -MemLimitMB $null -MemReservationMB 0 -MemSharesLevel "Normal"