A VMware vSphere Metro Storage Cluster (vMSC) configuration is a vSphere-verified solution that combines replication with array-based clustering. These configurations, commonly referred to as stretched storage clusters or metro storage clusters, are typically deployed in environments where disaster and downtime avoidance is a key requirement.
The best strategy for ensuring continuous uptime begins with mirroring identical copies of data between two places, ideally some distance apart from each other. Simply clustering servers and splitting them apart doesn’t provide adequate protection – especially if the shared storage array on which they rely is susceptible to a site failure. The vMSC architecture enables the subsystems to “stretch” the storage and the network between the two sites.
A better solution incorporates vSphere high-availability clusters with either SANsymphony Software-Defined Storage or DataCore Hyper-converged Virtual SAN products. SANsymphony is well suited when vSphere servers depend on an external SAN, and the clusters access it via iSCSI or Fibre Channel. When rolling out a hyper-converged configuration and keeping physical storage inside the servers, DataCore Hyper-converged Virtual SAN is ideal. For more details please see:
DataCore Metro Storage.
Hanover Hospital – The Benefits of DataCore and VMware vSphere Metro Storage Clusters
“The biggest benefit Hanover Hospital has experienced from adopting DataCore has been true high availability due to the automatically synchronized virtual disks that are mirror-protected and presented to different applications spanning our two on-campus data centers. Each data center shares critical workloads, yet provides physical separation of storage and compute in the event of a localized data center outage,” said Douglas Null, head of IT infrastructure at Hanover Hospital. “DataCore SANsymphony is our only storage solution and it delivers ‘no touch’ failover and failback operation. It delivers a fully automated process. Other vendor solutions are replicated as active/passive, need human intervention or scripts, or require other point products or special configurations to bring the passive site online.”
DataCore’s enterprise-class high-availability solution is designed to avoid equipment and site outages interrupting access to critical information flow. Combining SANsymphony and DataCore Hyper-converged Virtual SAN products in a stretched cluster configuration will enable VMware virtual machines to maintain continuous access to primary storage. DataCore products provide comprehensive and universal storage services that extend the capabilities of the storage devices managed by SANsymphony and DataCore Hyper-converged Virtual SAN software. The software can run on dedicated x86 servers with SANsymphony software or as a virtual machine (VM) on the hypervisor host with DataCore Hyper-converged Virtual SAN software.
“If access to the data is lost, everything goes down. Disruptions such as water damage, fire, construction and technician errors have proven that time and again,” said Augie Gonzalez, director of product marketing at DataCore. “In independent research, DataCore customers report preventing 100% of storage-related downtime, both planned and unplanned, and up to 75% reduction in storage costs to achieve the necessary levels of business continuity.”
DataCore software constantly mirrors data at high speeds between geographically separate locations with “zero downtime, zero touch” failover, designed to maximize business continuity. DataCore keeps active-active copies synchronized even when using different types of storage devices at each end. Stretched/metro clusters perceive the independent, mirrored copies as a single set of data, simultaneously reachable from either location over redundant paths.
When problems prevent applications from reaching the data at one location, failover to the mirrored copy occurs instantaneously and automatically without disruption, scripting or manual intervention. Similarly, the built-in automation takes care of resynchronization and failback to normal operations after the original cause of the outage is resolved. The comprehensive solution brings a common, integrated approach to continuous availability across the variety of applications, operating systems, hypervisors and storage hardware in place today and in the future.
