Novell BUSINESS CONTINUITY CLUSTERING 1.1 SP2 - ADMINISTRATION, Administration Manual

Page: 137 / 142

Configuring Host-Based File System Mirroring for NSS Pools
D
137
no
vd
ocx
(e
n)
13
Ma
y 20
09
D
Configuring Host-Based File
System Mirroring for NSS Pools
Several methods and scenarios exist for mirroring data between geographically separate sites. Each
method has its own strengths and weaknesses. For a Novell
®
Business Continuity Clustering
system, you need to choose either host-based mirroring or SAN-based mirroring (also called array-
based mirroring) and whether you want the mirroring to be synchronous or asynchronous.
Figure D-1
Synchronous Mirroring
IMPORTANT: The Business Continuity Clustering product does not perform data mirroring. You
must separately configure either SAN-based mirroring or host-based mirroring.
Storage-based synchronous mirroring is preferred and is provided by storage hardware
manufacturers. For information about storage-based mirroring, consult your storage system vendor
or see the storage system vendor documentation.
Host-based synchronous mirroring functionality is included with the Novell Storage Services
TM
(NSS) file system (NSS mirroring) that is part of NetWare 6.5. NSS mirroring is a checkpoint-based
synchronous mirroring solution. Data blocks are written synchronously to multiple storage devices.
It is an alternative to SAN-based synchronous replication options.
IMPORTANT: NSS pool snapshot technology does not work in a business continuity cluster.
Š Section D.1, “Creating and Mirroring NSS Partitions on Shared Storage,” on page 138
Server 6 Server 7 Server 5 Server 8
Fibre Channel
Switch
Building A Building B
Server 2 Server 3 Server 1 Server 4
Fibre Channel
Switch
Fibre Channel
Disk Array
Synchronous
Mirroring
Mirror Original
Ethernet Switch Ethernet Switch
Fibre Channel
Disk Array
Changes
Completion