Справочник Пользователя для Hitachi 9900 Series

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

™

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 support 
alternate pathing for AIX

®

4.2 and above, Compaq True64

™

UNIX

®

, HP

®

10.01 

and through PVlink, Windows NT/2000

®

and Sun Solaris

™

2.5 and Sequent 

DYNIX/ptx

®

. In addition, VERITAS

®

Dynamic Path Management

™

(DPM) is 

supported.

Hitachi Dynamic Link Manager

™

is a family of Hitachi-provided middleware     

software utilities that are server-based as shown in Figure 22. Hitachi 
Dynamic Link Manager

™

enhances the availability of RAID systems by providing 

automatic error recovery and path failover from server-to-RAID connection     
failures. Hitachi Dynamic Link Manager

™

provides 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 Hitachi Data Link Manager

™

is required for

true non-stop operations. This product allows systems administrators to take 
advantage of the multiple paths on a Lightning 9900

™

by adding redundant    

connections between application servers and RAID systems. Hitachi Dynamic 
Link Manager

™

therefore provides increased reliability and performance. 

Supported platforms include AIX

®

, Sun Solaris

™

, Windows NT

®

, and Windows 

2000

®

.

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

™

supports all major open systems clustering schemes      

including: Compaq TruCluster

®

, HP

®

MC Service Guard, HP

®

MC Lock 

Manager, IBM

®

RS6000 and SP HACMP, Windows NT/2000

®

, Microsoft

®

Cluster Server, NCR

®

UNIX

®

SVR4 Lifekeeper, IBM DYNIX/ptx ATAP

®

, and 

VERITAS ClusterServer

™

for Sun Solaris

™

.

27