Quorum device management (external NAS Manager only)

Server and Cluster Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS010-35

An external NAS Manager hosts a pool of eight quorum devices (QDs). The NAS Manager provides quorum services for up to eight clusters from its pool of QDs by assigning a QD to a cluster during cluster configuration. After being assigned to a cluster, the QD is “owned” by that cluster and is no longer available for assignment to another cluster. Removing a QD from a cluster releases ownership of the QD and returns the QD to the NAS Manager’s pool of available QDs.

Beginning in NAS Manager software version 10.0, an updated quorum service is available. Depending on version of the NAS server firmware in clusters managed by the NAS Manager, one or both of the following quorum service versions may be required:
  • Quorum Services (also known as legacy Quorum Services) is required by clusters running firmware versions prior to version 10.0.
  • Quorum Services v2 is used by clusters running firmware versions 10.0 and newer.
Note: Unified VSP Gx00 with NAS modules and VSP N series models can have a maximum of two nodes. All other details described here apply to the HNAS server models.

NAS Managers running software version 10.0 and later can simultaneously manage clusters that require legacy Quorum Services and other clusters that require Quorum Services v2. Non-managed servers may also use the quorum services on the NAS Manager.

Note: During cluster configuration, the two quorum service versions work together to ensure that one cluster cannot be served by QDs of both quorum services at the same time. When a request is made to assign a QD to a cluster, the quorum service receiving the request first checks if the other quorum service has already assigned a QD to the cluster. If so, the previously assigned QD is removed from the cluster before the quorum service receiving the request assigns a QD to the cluster. This ensures that the old and new quorum services cannot both service the same cluster.