Storage DRS extends the DRS feature set to the storage space. The primary element used by SDRS is a datastore cluster. Introducing the concept of datastore clusters can affect or shift the paradigm of storage management in virtual infrastructures. This article is the start of a short series of articles focusing on the design considerations of datastore clusters
Datastore cluster concept
Let’s start with looking at the concept datastore cluster. Datastore clusters can be regarded as the equivalent of DRS clusters. A datastore cluster is the storage equivalent of an vCenter (DRS) cluster whereas a datastore is the equivalent of a ESXi host. As datastore clusters pool storage resources into one single logical pool it becomes a management object. This storage pooling allows the administrator to manage many individual datastores as one element, and depending on the enabled SDRS features, providing optimized usage of storage capacity and IO performance capability off all member datastores.
SDRS settings are configured at datastore cluster level and are applied to each member datastore inside the datastore cluster. When SDRS is enabled the datastore cluster it becomes the storage load-balancing domain, requiring administrators and architects to treat the datastore cluster as a single entity for decision making instead of individual datastores.
Datastore Clusters architecture and design
Although datastore clusters offers an abstraction layer, one must keep in mind the relationship between existing objects like hosts, clusters, virtual machine and virtual disks. This new abstraction layer might even disrupt existing (organizational) processes and policies. Introducing datastore clusters can have impact on various design decisions such as VMFS datastores sizing, configuration of the datastore clusters, the variety in datastore clusters and the number of datastore clusters in the virtual infrastructure.
In this series I will address these considerations more in depth. Stay tuned for the first part; the impact of connectivity of datastores in a datastore cluster.
More articles in the architecting and designing datastore clusters series:
Part2: Partially connected datastore clusters.
Part3: Impact of load balancing on datastore cluster configuration.
Part4: Storage DRS and Multi-extents datastores.
Part5: Connecting multiple DRS clusters to a single Storage DRS datastore cluster.