Datastore cluster requirements
Datastores and hosts that are associated with a datastore cluster must meet certain requirements to use datastore cluster features successfully. Follow these guidelines when you create a datastore cluster:
- Datastore clusters should contain similar or interchangeable datastores.
- On the PowerMax, all datastores in a datastore cluster should have the same service level.
- A datastore cluster can contain datastores with different sizes and I/O capacities and can be from different arrays and vendors. Nevertheless, Dell Technologies does not recommend mixing datastores that are backed by devices that have different properties.
- NFS and VMFS datastores cannot be combined in the same datastore cluster. vVol datastores are not supported.
- If TimeFinder protects VMFS volumes, do not mix and match protected and nonprotected devices in a datastore cluster. If SDRS is enabled, only manual mode is supported with datastores that TimeFinder protects.
- Datastores that are shared across multiple data centers cannot be included within a datastore cluster.
- As a best practice, do not include datastores that have hardware acceleration enabled in the same datastore cluster as datastores without hardware acceleration enabled. Datastores in a datastore cluster must be homogeneous to guarantee consistent hardware acceleration-supported behavior.
- Replicated datastores cannot be combined with nonreplicated datastores in the same Storage DRS enabled datastore cluster. If SDRS is enabled, only manual mode is supported with replicated datastores.
- Do not mix and match replication modes and solutions within a datastore cluster. For example, do not have SRDF/A and SRDF/S protected devices within the same datastore cluster or mix Dell RecoverPoint and SRDF devices.
- If a device is contained in a consistency group and that device is part of a datastore cluster, do not add devices into that datastore cluster that are not protected by that consistency group. This practice maintains proper consistency. It also ensures that a VM with consistency dependencies on other VMs does not move out of the consistency group due to a Storage DRS move. In general, a datastore cluster should have a one-to-one relationship with a consistency group.
Storage DRS and Storage vMotion on datastores that VMware vCenter Site Recovery Manager manages are supported. There are some rules. Storage vMotion or SDRS movements must be limited to devices within a single consistency group. Therefore, for things like datastore clusters, it is required to have only devices in the same consistency group in the cluster. VMware does not allow SDRS to violate these rules and permits greater flexibility with SDRS. Consult the VMware SRM documentation for more information.