Cisco HyperFlex storage clusters contain the following objects. These objects are monitored by the HX Data Platform for the storage cluster. They can be added and removed from the HX storage cluster.
Converged nodes: Converged nodes are the physical hardware on which the VM runs. They provide computing and storage resources such as disk space, memory, processing, power, and network I/O. When a converged node is added to the storage cluster, a storage controller VM is installed. The HX Data Platform services are handled through the storage controller VM. Converged nodes add storage resources to your storage cluster through their associated drives.
Compute nodes: Compute nodes add compute resources but not storage capacity to the storage cluster. They are used as a means to add compute resources, including CPU and memory. They do not need to have any caching (SSD) or storage (HDD) drives. Compute nodes are optional in an HX storage cluster.
Drives: There are two types of drives that are required for any node in the storage cluster: SSDs and HDDs. HDDs typically provide the physical storage units associated with converged nodes. SSDs typically support management. Adding or removing disks on your converged nodes is not performed through the HX Data Platform.
Datastores: These datastores provide storage capacity and datastore capacity. This is the combined consumable physical storage available to the storage cluster through datastores and managed by the HX Data Platform. Datastores are logical containers that are used by the HX Data Platform to manage your storage use and storage resources. Datastores are where the host places virtual disk files and other VM files. Datastores hide the specifics of physical storage devices and provide a uniform model for storing VM files.
HX Data Platform High Availability
The HX Data Platform high availability feature ensures that the storage cluster maintains at least two copies of all your data during normal operation with three or more fully functional nodes.
If nodes or disks in the storage cluster fail, the cluster’s ability to function is affected. If more than one node fails or one node and disk(s) on a different node fail, it is called a simultaneous failure.
The number of nodes in the storage cluster and the Data Replication Factor and Access Policy settings determine the state of the storage cluster that results from node failures.
HX Data Platform storage cluster status information is available through HX Connect, the HX Data Platform plug-in, and the storage controller VM stcli commands. Storage cluster status is described through resiliency and operational status values. Storage cluster status is described through the following reported status elements:
Operational status: Describes the ability of the storage cluster to perform the storage management and storage cluster management functions of the cluster. Describes how well the storage cluster can perform operations.
Resiliency status: Describes the ability of the storage clusters to tolerate node failures within the storage cluster. Describes how well the storage cluster can handle disruptions.
The following settings take effect when the storage cluster transitions into particular operational and resiliency status states:
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