An alternative to using datastore groups for protection groups is tag-based storage policies. Storage policies allow for greater flexibility via a few ways:
- Virtual machines can be migrated between datastores manually or automatically and storage policies will make sure they remain on the correct datastores
- If a new replicated datastore is provisioned and new VMs put on it (or pre-existing ones are moved to it) the datastore will automatically be added to the SRM protection group for the corresponding policy
- Datastores for different array pairs can be added to the same SRM protection group
- Only method supported for stretched storage-protected VMs
Note that VMs that are on ActiveCluster volumes can be protected in two ways; either via the stretched storage feature of SRM (long distance vMotion of the VMs between arrays, or disaster restart) that keeps the volumes on the stretched volumes, or the via asynchronous periodic replication from an ActiveCluster pod to a third remote array. The former method must be configured with storage policy-based protection groups. The latter method (failover to third array) can be protected by either a storage policy-based protection group or a traditional datastore group-based protection group.
The main limitation around storage policy-based protection groups is that they do not support virtual machines with Raw Device Mappings. For VMs with RDMs, you must use datastore group-based protection groups.
Note that for VMs and datastores to be protected via storage policies, tags and tag categories must be configured, tags must be assigned, the policies must be created, and policies must be assigned to the VMs on the datastores. See SRM User Guide: Configuring Site Recovery Manager (8.4 and lower) Tag-Based Storage Policy Discovery for more detail.
To add a storage policy to a protection group, choose Storage Policies.
Then choose one or more storage policies to add to the protection group. This should be a tag-based storage policy; SRM will not filter out non-applicable policies.