A: VMware’s load-balancing DRS service operates at five-minute intervals. At each interval, the service calculates how balanced (or imbalanced) the cluster is and generates migration recommendations if necessary. This means that every five minutes, new migration recommendations can appear in your cluster’s DRS tab if it's set to Manual.
While not recommended, it's possible to adjust this interval value. Do so by editing the file C:\Users\All Users\Application Data\VMware\VMware VirtualCenter\vpxd.cfg on your vCenter Server. Search for the following code and adjust its value in seconds to change DRS’ interval:
<config> <drm> <pollPeriodSec> 300 </pollPeriodSec> </drm> </config>