Understanding HNAS multi-tenancy benefits

Server and Cluster Administration Guide for Hitachi NAS Platform

Part Number

Using HNAS multi-tenancy can help you avoid some of the challenges faced with traditional multi-tenant environments.

Commonly, HNAS customers who are ASPs (Internet services providers and managed services providers) sell their services to their customers. Their customers are the tenants in a multi-tenant environment. The ASPs cannot force their tenants into a specific subnet, which means that the ASPs run into issues when some tenants use the same network address scheme.

In the past, this situation caused overlapping IP addresses and networks on the HNAS EVSs. The IP routing and networking settings were global on an HNAS server--per-EVS settings were unsupported. The HNAS multi-tenancy feature allows you to set up all the different tenant networks as VLANs and then allocate them to the specific EVSs. These networks may have the same IP subnet but may be different gateways in their VLAN-segregated networks.

Other common challenges that HNAS multi-tenancy addresses include the following:
  • Tenant's configurations could contain the same names but identify different things to those tenants. For example, the names could identify NIS domain, Windows domain, or virus scanners.
  • Tenant's networks could have the same address range. They could be in the same or different subnets from each other.
  • Tenant's networks could be using the same IP address for something, but the server is really a different server. For example, it's common practice to use the first or last IP address in a given subnet to be the router for that network, so the same IP address could be referring to many different routers for different customers.
  • Looking up a name from a given IP address may give different names for different tenants.
  • Looking up an IP address from a name may give different IP addresses for different tenants. Even if they resolve to the same IP address, they may be completely different hosts.