Sizing Considerations
There are a number of sizing issues to consider when setting up your disaster recovery. Review the 
Zerto Scale and Benchmarking Guidelines to see the sizing considerations.
To adjust the VMDK size limitation:
1.	Log in to vCenter Server or the ESX/ESXi host using VMware Infrastructure (VI) Client. If connecting to vCenter Server, select the ESX/ESXi host from the inventory. 
2.	Click the Configuration tab.
3.	Click Advanced Settings. 
4.	Select VMFS3.
5.	Update the field in VMFS3.MaxHeapSizeMB.
■	In ESXi 5.x, the maximum heap size is 256MB.
6.	Reboot the host for the changes to take effect.