HP StorageWorks 8000, Руководство пользователя

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HP NAS 8000 Concepts
32 HP StorageWorks NAS 8000 User’s Guide
Understanding High Availability
Note: This section applies only if you have a high-availability NAS solution.
High availability systems are designed to avoid a loss of service by reducing or
managing failures and minimizing downtime. High availability implies a service
level in which both planned and unplanned downtime is minimized.
Cluster Components
The NAS 8000 cluster consists of two NAS servers, a quorum server and storage
that may come from either a dedicated storage configuration or a SAN. The NAS
servers share access to the storage and provide failover capabilities for each other,
but function as independent servers.
The main purpose of high-availability clusters is to provide a higher degree of
storage availability to client systems than is possible with a single server. This is
accomplished by minimizing single points of failure and providing functional
redundancy. Server downtime and interruptions to storage availability are
minimized by failing over file serving capabilities between the NAS servers in the
event of a failure in either server.
Failover Models
Failover is a backup operational mode in which the functions of one NAS server
are assumed by the other NAS server if either server becomes unavailable through
failure or scheduled down time.
Supported modes are:
■
Active/Active
■
Active/Passive