Alternate Pathing Middleware Switches The I/O Load In The Event Of Path Failure; Hitachi Dynamic Link Manager Provides Path Failover And Load Balancing; Host Failover - Hitachi Lighting 9900 Series Architecture Manual

There are four basic types of high-availability middleware that can reduce downtime in
the event of a data path or host failure. The Lightning 9900
middleware:
1. Alternate Pathing middleware switches the I/O load in the event of
path failure
This type of middleware automatically switches the I/O load on a failed primary
path to an alternate path on the same host system. The Lightning 9900 support
alternate pathing for AIX
and through PVlink, Windows NT/2000
DYNIX/ptx . In addition, VERITAS
®
supported.
2 . Hitachi Dynamic Link Manager
balancing
Hitachi Dynamic Link Manager
software utilities that are server-based as shown in Figure 22. Hitachi
Dynamic Link Manager
automatic error recovery and path failover from server-to-RAID connection
failures. Hitachi Dynamic Link Manager
path failover by re-directing I/O activity to the least busy path using complex
algorithms.
Just because a system is RAID-protected doesn't mean it is protected against
connection bus failures, which is why Hitachi Data Link Manager
true non-stop operations. This product allows systems administrators to take
advantage of the multiple paths on a Lightning 9900
connections between application servers and RAID systems. Hitachi Dynamic
Link Manager therefore provides increased reliability and performance.
™
Supported platforms include AIX
2000 .
®

3. Host Failover

Host failover software supports a cluster of host processors in which one of the
hosts automatically takes over the workload of any failed host in the cluster. This
"take-over" includes the reassignment of networks and peripherals, as well as the
restarting of applications. Host clustering can also be used to create fault-tolerant
work loads and scale processor capability while sharing network and disk
resources.
The Lightning 9900
including: Compaq TruCluster
Manager, IBM RS6000 and SP HACMP, Windows NT/2000
®
Cluster Server, NCR
VERITAS ClusterServer
Hitachi High Availability Software Improves Application Service Levels
® 4.2 and above, Compaq True64
and Sun Solaris
®
Dynamic Path Management
®
™ provides path failover and load
is a family of Hitachi-provided middleware
™
™ enhances the availability of RAID systems by providing
provides load balancing in addition to
™
, Sun Solaris
® ™
™ supports all major open systems clustering schemes
, HP MC Service Guard, HP
® ®
® UNIX ® SVR4 Lifekeeper, IBM DYNIX/ptx ATAP
for Sun Solaris .
™ ™
supports each classification of
™
™ UNIX ® , HP ® 10.01
2.5 and Sequent
™
(DPM) is
™
™ is required for
by adding redundant
™
, Windows NT , and Windows
®
MC Lock
®
, Microsoft
®
® , and
Alternate pathing
automatically switches
the I/O load on a failed
primary path.
Hitachi Dynamic Link
Manager ™
balancing in addition to
path failover.
One of the hosts
automatically takes
over the workload of any
failed host in the cluster.
®
provides load
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