Hitachi 9900 Manual De Usuario

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 V Series supports each
classification of middleware:

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 V Series 
systems support alternate pathing for IBM AIX

®

, HP

®

True64

™

UNIX

®

,

HP-UX

®

and through PVlink, Microsoft

®

Windows NT

®

/Windows

®

2000, Sun

™

Solaris

™,

and IBM DYNIX/ptx

®

.

Hitachi Dynamic Link Manager

™

software is a family of Hitachi-provided 

middleware software utilities that are ser ver-based, as shown in Figure 22. 
Dynamic Link Manager software enhances the availability of RAID systems by
providing automatic-error recovery and path failover from server-to-RAID 
connection failures. Dynamic Link Manager software pr ovides load balancing in 
addition to 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 Dynamic Link Manager software is required
for true nonstop operations. This product allows systems administrators to take 
advantage of the multiple paths on a Lightning 9900 V Series system by adding 
redundant connections between application ser vers and RAID systems. Dynamic 
Link Manager software therefore provides increased reliability and performance. 
Supported platforms include IBM AIX, Sun Solaris, Windows NT,
Windows 2000, and LINUX

®

(July 2003).

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 
“takeover” includes the reassignment of networks and peripherals, as well as the 
restarting of applications. Host clustering can also be used to create fault-tolerant 
workloads and scale processor capabilities while sharing network and disk 
resources.

Lightning 9900 V Series systems supports all major open systems clustering 
schemes including: HP TruCluster

™

, HP MC/ServiceGuard

™

, HP MC/Lock 

Manager, IBM RS6000

®

and SP HACMP

™

, Windows NT/Windows 2000, 

Microsoft Cluster Server, NCR UNIX SVR4 Lifekeeper, IBM DYNIX/ptx ATAP,
VERITAS Cluster Server

™

for Sun Solaris and Red Hat

®

Advanced Server 2.1 

and SuSE Enterprise Server 7.0 for LINUX

®

.

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