Novell BUSINESS CONTINUITY CLUSTERING 1.1 SP2 - ADMINISTRATION, Administration Manual

Page: 21 / 142

Overview 21
no
vd
ocx
(e
n)
13
Ma
y 20
09
1.3 Novell Business Continuity Clusters
A Novell Business Continuity Clustering cluster is an automated cluster of Novell Cluster Services
clusters. It is similar to what is described in
“Cluster of Clusters” on page 16 , except that the cluster
configuration, maintenance, and synchronization have been automated by adding specialized
software.
BCC supports up to four peer clusters. The sites are geographically separated mirrored data centers,
with a high availability cluster located at each site. Configuration is automatically synchronized
between the sites. Data is replicated between sites. All cluster nodes and their cluster resources are
monitored at each site. If one site goes down, business continues through the mirrored sites.
The business continuity cluster configuration information is stored in eDirectory. eDirectory schema
extensions provide the additional attributes required to maintain the configuration and status
information of BCC enabled cluster resources. This includes information about the peer clusters, the
cluster resources and their states, and storage control commands.
BCC is an integrated set of tools to automate the setup and maintenance of a business continuity
infrastructure. Unlike competitive solutions that attempt to build stretch clusters, BCC uses a cluster
of clusters. Each site has its own independent clusters, and the clusters in each of the geographically
separate sites are each treated as “nodes” in a larger cluster, allowing a whole site to do fan-out
failover to other multiple sites. Although this can currently be done manually with a cluster of
clusters, BCC automates the system by using eDirectory and policy-based management of the
resources and storage systems.
Other
Considerations
Š
Host-based mirroring is required to
mirror the SBD partition between
sites.
Š
Link variations can cause false
failovers.
Š
You could consider partitioning the
eDirectory tree to place the cluster
container in a partition separate from
the rest of the tree.
Š
The cluster heartbeat tolerance
between master and slave must be
increased to accommodate link
latency between sites.
You can set this as high as 30
seconds, monitor cluster heartbeat
statistics, and then tune down as
needed.
Š
Because all IP addresses in the
cluster must be on the same subnet,
you must ensure that your switches
handle ARP.
Contact your switch vendor or
consult your switch documentation
for more information.
Š
Depending on the platform used,
storage arrays must be controllable
by scripts that run on NetWare
®
if
the SANs are not SMI-S compliant.
Stretch Cluster Cluster of Clusters