Configuring Nss Mirroring - Novell BUSINESS CONTINUITY CLUSTERING 1.0 - ADMINISTRATION Manual

NSS mirroring is a checkpoint-based synchronous mirroring solution. Data blocks are written
synchronously to multiple storage devices. It is an alternative to SAN array-based synchronous
replication options.
Figure 2-2
Server 1
Fibre Channel

2.8.1 Configuring NSS Mirroring

NSS partitions must be mirrored after they are created. If you have an existing partition that you
want to mirror, you can either create another partition of equal size on another device to mirror the
first partition to, or let the mirroring software automatically create another partition of equal size on
another device.
When you create a Novell Cluster Services system that utilizes shared storage space (a Storage Area
Network or SAN), it is important to remember that all servers attached to the shared device, whether
in the cluster or not, have access to all of the volumes on the shared storage space unless you
specifically prevent such access. Novell Cluster Services arbitrates access to shared volumes for all
cluster nodes, but cannot protect shared volumes from being corrupted by noncluster servers.
Creating and Mirroring NSS Partitions on Shared Storage
Prior to creating and mirroring NSS partitions on shared storage, ensure that you have
26 Novell Business Continuity Cluster Services 1.0 Administration Guide
Synchronous Mirroring
Building A
Ethernet Switch
Server 2 Server 3
Switch
Fibre Channel
Disk Array
Original
All servers in the cluster connected to a shared storage system
One or more drive arrays configured on the shared storage system
At least 15 MB of free space on the shared storage system for a special cluster partition
Synchronous
Mirroring
Server 4
Changes
Completion
Building B
Ethernet Switch
Server 5 Server 6 Server 7
Fibre Channel
Switch
Fibre Channel
Disk Array
Mirror
Server 8