Private cloud storage is a service model for provisioning storage to users in an organization. Just like a private cloud offers compute resources on-demand (for example, Linux machines), it can also offer storage on-demand, with the same private cloud capabilities: on-demand access, resource pooling, elasticity and metering.
Organizations usually invest in private cloud storage to satisfy compliance or security requirements. Another use case is on-premises applications that require high-latency or high-throughput access to data, making it necessary to place the storage physically near to the storage consumer.