How Site Recovery Manager Interacts with Stretched Storage

Stretched storage support is available for array-based replication.

Site Recovery Manager supports active-active stretched storage between protected and recovery sites by using Cross vCenter Server vMotion to perform planned migrations, eliminating service downtime. Disaster recovery and test recovery continue to use the existing LUN-based recovery functionality.

Important: Stretched storage is supported only on vCenter Single Sign-On Enhanced Linked Mode environments. Planned migration with Cross vCenter Server vMotion fails if the sites are not Enhanced Linked Mode. Stretched storage is required when using Cross vCenter Server vMotion during a planned migration.

Protection Groups

Important: Protection groups for stretched storage must be created as storage policy protection groups or array-based replication protection groups. For storage policy protection groups, you must create and use storage profiles to protect and recover stretched storage devices.

• Protection groups with stretched devices must have a preferred direction from the protected site to the recovery site. The preferred direction must match the site preference that the array maintains for the corresponding devices. If the array supports site preference, then the protected site must have the site preference.
• Stretched and nonstretched virtual machines and consistency groups can be in the same protection groups and the same recovery plan.
• The stretched virtual machines must be on a stretched datastore and must be powered on at the protected site.
• You cannot create two protection groups in opposite directions by using the same stretched device pair. You can place virtual machines on the stretched devices at the recovery site that correspond to protected devices at the protected site, but if the recovery site ESXi is mounting the protected site storage there is a risk of data corruption. You cannot protect these virtual machines, but they are automatically protected during the reprotect process.

Planned Migration

• The Run Recovery Plan wizard has an option to use Cross vCenter Server vMotion to perform a planned migration. If the option is selected, Cross vCenter Server vMotion is used for all protected, powered-on virtual machines on the stretched storage at the protected site. If the option is not selected, the regular recovery workflow is used for replicated LUNs, including stretched storage.
• If Cross vCenter Server vMotion fails for any reason, the recovery plan stops at the "Migrating VMs" step and does not continue. If you cannot resolve the problem that is preventing Site Recovery Manager from using Cross vCenter Server vMotion for your storage policy protection groups, rerun the recovery plan with the vSphere vMotion option turned off. For array-based replication protection groups, restore the placeholder virtual machines for the VMs for which vMotion failed and then rerun the recovery plan with the vSphere vMotion option turned off. The migration can then use the regular recovery workflow for replicated LUNs.
• During the deactivate step the stretched devices stay mounted at the protected site even if vMotion is not used. Site Recovery Manager ignores non-protected replica virtual machines on the stretched devices at the protected site and does not unregister them.

Test Recovery

• Test recovery is performed by using the regular test recovery workflow for replicated devices, including stretched devices. vMotion compatibility checks are performed for each virtual machine on the stretched devices.
• If the array does not support creating read-write snapshots for stretched devices, Site Recovery Manager does not allow you to perform a test recovery for these devices.

Cross vCenter Server vMotion

Cross vCenter Server vMotion is not supported for migration from a vSphere Distributed Switch port group to a standard switch network. In this instance, attempting to Cross vCenter Server vMotion a virtual machine results in these error messages.

• Unable to find a host in the cluster <cluster-name> that is compatible with the Cross vCenter Server vMotion of the virtual machine <vm-name> from the protection group <PG-name>.
• Currently connected network interface <network-adapter-name> cannot use network <network-name>, because the type of the destination network is not supported for vMotion based on the source network type.

Cross vCenter Server vMotion does not work in these situations.

• If the distributed resource scheduler is deactivated for the cluster
• If the virtual machine has snapshots
• If the virtual machine is a linked clone
• If the virtual machine is attached to RDM devices

Cross vCenter Server vMotion requirements in vSphere are discussed in the ESXi and vCenter Server 7.0 documentation.