#Vmware vcenter server appliance update bundle manual
Disable DRS or keep in manual in the settings of the vCenter server VM cluster.Copy migration-assistant folder from VCSA 6.5 ISO to your VUM server and keep VMware-Migration-Assistant running until the upgrade process completes.Identify an ESXi host to place the new vCenter 6.5 during the Upgrade process and keep the host credentials ready.There is a common issue during most of upgrades with vCenter Server SSL certificate, it is good to regenerate the SSL certificate before starting the upgrade process or do the same if the pre-upgrade check throws error.Keep all the components in your VCSA 5.5 environments has NTP configured and synced.