How much retention is there on the DRS and vMotion logs

Hi Experts,

I have been asked to produce the last 6 months off all the vMotions between hosts in a cluster. More specifically, we are concerned with vMotions that originate from DRS. I looked at the history for DRS and it is very minimal (last 4 hours). I search through the DRS logs in the C:|programdata\vmware\VMware VirtualCenter\Logs\drmdump folder and was not able to interpret them. I looked in vCenter and attempted to browse through the logs here also. My question, is how much retention is there on the DRS and vMotion logs and is there a way to produce a report of this information showing the VM, time of each vmotion, if DRS initiated it or user initiation?

Thanks

SD