SAN Configurations for RA8000/ESA12000 on Windows NT - Intel
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Product Overview
The RA8000 and ESA12000 FC storage systems are based on a common architecture and offer
customers centralized management, high availability, and exceptional performance and scalability in
open systems environments. These products provide a Fibre Channel storage solution with industry
leading SAN support utilizing both FC-Fabric (switch) and FC-AL (arbitrated loop) technology.
The RA8000 FC is a mid-range storage system available in a pedestal enclosure for departmental use
in the office. It can also be installed in server racks for small data centers. An easy-to-deploy, flexible
solution for open systems, the RA8000 supports up to 2.6 TB of storage.
The ESA12000 FC, designed for the data center, is available in three easy-to-order building blocks;
each optimized for specific, high-capacity customer requirements. The ESA12000 FC offers
unprecedented levels of storage, scaling in performance and capacity as user requirements increase.
These storage systems incorporate the latest in RAID technology providing RAID levels 0, 1, 0+1,
adaptive 3/5, and non-RAID disks. Compaq’s implementation of RAID capability assures that data
availability will be maintained despite hardware failure. Features such as read ahead cache and
mirrored write back cache improve or minimize the affect on performance while preserving data
availability and supporting high availability.
The RA8000/ESA12000 FC platform kits contain the necessary operating system specific software
and documentation needed to install, configure, and monitor your storage system. All platform kits
include the StorageWorks Command Console (SWCC) for storage management operations including
configuring, status inquiry and notification facilities. SWCC provides a user oriented graphical user
interface (GUI) simplifying the most complex of storage management operations.
Microsoft Cluster Server (MSCS)
A Windows NT MSCS cluster enables two servers to share an RA8000 or ESA12000 FC storage
system through a Fibre Channel bus. If a server failure should occur, the storage I/O is re-routed
through to the functioning server. This process, called cluster failover, requires no resource
downtime ensuring the high availability of data.
The RA8000 and ESA12000 FC storage systems are supported in Windows NT MSCS cluster
configurations. All of the cluster configurations provide full cluster failover capabilities through a
fibre channel bus connected to both cluster servers.
In addition to cluster failover, the RAID array controllers can be configured in transparent failover
mode to protect against the unlikely event of a single controller failure. This feature eliminates
controllers as single points of failure and is invoked without the need for server intervention.
For the highest availability, two hardware paths between the cluster servers and the RA8000 or
ESA12000 FC storage system can be configured using Compaq’s Secure Path for Windows NT. This
configuration provides two separate physical paths between the servers and the storage.
Secure Path for Windows NT
StorageWorks Secure Path is a high availability software product providing continuous data access
for RA8000 and ESA12000 FC storage products configured on Windows NT platforms. Redundant
hardware, advanced RAID technology and automated failover capability are used to enhance fault
tolerance and availability. Secure Path effectively eliminates controllers, interconnect hardware and
host bus adapters as single points of failure in the storage system.
Key to Secure Path’s functionality is the capability of RA8000/ESA12000 FC dual HSG80
controllers to operate in the active/active Multiple-Bus failover mode. This failover mode allows each
controller to be configured on its own bus and to process I/O independently under normal operation.
Available storage units are “preferred” to one or the other of the two controllers which determines
which controller path is used for access at system boot time. During runtime, storage units may be
moved between paths at anytime through use of the management utility without disrupting operations.
