Cross hypervisor disaster recovery (CHDR) provides the ability to migrate the VMs from one
hypervisor to another (ESXi to AHV or AHV to ESXi) by using the protection domain semantics
of protecting VMs, generating snapshots, replicating the snapshots, and then recovering the
VMs from the snapshots

Key notes

1. install and configure NGT on all the VMs
2. When you recover VMs from the AHV hypervisor on the ESXi hypervisor, the VMs come up with E1000 NIC attached by default. However, if you want to bring the VMs up withVMXNET NIC is attached, you must install VMware Tools
3. Static IP address preservation is not supported for CHDR workflows. If a VM has an astatic IP address configured, you must manually reconfigure the VM IP address after its recovery on the target site.
4. Hypervisor-specific properties like multi-writer flags, independent persistent and independent non-persistent disks, or changed block tracking (CBT) is not preserved in the CHDR operation

Requirements

1. Nutanix supports only VMs with flat files. Nutanix does not support vSphere snapshots
   or delta disk files. If you have delta disks attached to the VM and you proceed with the
   migration, the VMs are lost
2. Nutanix does not support VMs with attached volume groups or shared virtual disks
3. Nutanix supports IDE/SCSI and SATA disks only. PCI/NVMe disks are not supported
4. Nutanix supports CHDR on both the sites with all the AOS versions that are not EOL
5. Set the SAN policy to OnlineAll for all the Windows VMs for all the non-boot SCSI disksso that they can automatically be brought online. For more information about setting SANpolicy, see Bringing Multiple SCSI Disks Online on page 208
6. (For migration from AHV to ESXi) Automatic reattachment of iSCSI-based volume groups(VGs) fails after VMs are migrated to ESXi because vCenter and, in turn, the Nutanix cluster do not obtain the IP addresses of the VMs. Therefore, after migration, manually reattach theVGs to the VMs
7. Do not enable VMware vSphere Fault Tolerance (FT) on VMs that are protected with CHDR.If already enabled, disable VMware FT. VMware FT does not allow registration of VMs. enabled with FT on any ESXi node after migration. This also results in a failure or crash of Uhura service

Limitations of CHDR

1. Nutanix cluster nodes to vSphere cluster mapping: The Nutanix data distribution architecture
   does not support the mapping of the nodes of a Nutanix cluster to multiple vSphere clusters
2. Ensure that all the nodes in the Nutanix cluster are in the same vSphere (ESXi) host cluster and that the network is available on all the nodes in the Nutanix cluster at the primary or remote site. Any configuration using Nutanix DR where there is more than one ESXi cluster on top of a single Nutanix cluster is not supported
3. Recommends that each application that constitutes a set of entities is protected by a unique protection domain
4. Supports one snapshot per hour as the shortest possible snapshot frequency for asynchronous replication
5. Does not support snapshots of the entire file systems or storage containers
6. Supports a VM to be a part of a protection domain only if the VM is entirely on a Nutanixdatastore and not on an external storage
7. Does not support running multiple third-party backups in Parallel on the same set of VMs.The system becomes unstable
8. Does not support VMX editing when you restore a VM. As a result, the characteristics of the restored VM such as MAC addresses may be in conflict with other VMs in the cluster
9. The replication speed reduces when deduplication is enabled on storage containers containing protected VM

for more details