You must create inventory mappings so that Site Recovery Manager can create placeholder virtual machines.
Inventory mappings provide a convenient way to specify how Site Recovery Manager maps virtual machine resources at the protected site to resources at the recovery site. Site Recovery Manager applies these mappings to all members of a protection group when you create the group. You can reapply mappings whenever necessary, for example when you add new members to a group.
Site Recovery Manager does not enforce an inventory mapping requirement. If you create a protection group without defining inventory mappings, you must configure each protected virtual machine individually or use the Configure All option. Site Recovery Manager cannot protect a virtual machine unless it has valid inventory mappings for key virtual machine resources.
After you configure mappings at the protected site when you configure protection, configure inventory mappings at the recovery site to enable reprotect.
When Site Recovery Manager creates a placeholder virtual machine, Site Recovery Manager derives its folder and compute resource assignments from inventory mappings that you establish at the protected site. A vCenter Server administrator at the recovery site can modify folder and compute resource assignments as necessary.
Configuring Inventory Mappings for Individual Virtual Machines
You can configure mappings for individual virtual machines in a protection group. If you create inventory mappings for a site, you can override them by configuring the protection of individual virtual machines. If you must override inventory mappings for some members of a protection group, use the vSphere Client to connect to the recovery site, and edit the settings of the placeholder virtual machines or move them to a different folder or resource pool.
Changing Inventory Mappings
If you change existing inventory mappings for a site, the changes do not affect virtual machines that Site Recovery Manager already protects. Site Recovery Manager only applies the new mappings to newly added virtual machines or if you repair a lost placeholder for a particular virtual machine.
Because placeholder virtual machines do not support NICs, you cannot change the network configurations of placeholder virtual machines. You can only change the network for a placeholder virtual machine in the inventory mappings. If no mapping for a network exists, you can specify a network when you configure protection for an individual virtual machine. Changes that you make to the placeholder virtual machine override the settings that you establish when you configure the protection of the virtual machine. Site Recovery Manager preserves these changes at the recovery site during the test and recovery.
How Site Recovery Manager Applies Mappings During Reprotect
During reprotect, Site Recovery Manager converts the virtual machines from the original protected site into placeholders, to protect the recovered virtual machines that were formerly the placeholder virtual machines on the recovery site. In most cases, the previously protected virtual machines and their devices are used during reprotect. If you add devices to a virtual machine after the virtual machine is recovered, or if original protected virtual machines are deleted, Site Recovery Manager uses mappings during reprotect.