Novell BUSINESS CONTINUITY CLUSTERING 1.2.1 - ADMINISTRATION, Руководство администратора

Страница: 20 / 184

20 BCC 1.2.1: Administration Guide for OES 2 SP2 Linux
no
vd
ocx
(e
n)
7 Ja
nua
ry 201
0
1.3 Business Continuity Clustering
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.
Disadvantages
Š
The eDirectory partition must span
the sites.
Š
Failure of site interconnect can
result in LUNs becoming primary at
both locations (split brain problem) if
host-based mirroring is used.
Š
An SBD partition must be mirrored
between sites.
Š
It accommodates only two sites.
Š
All IP addresses must reside in the
same subnet.
Š
Resource configurations must be
manually synchronized.
Š
Storage-based mirroring requires
additional configuration steps.
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 OES 2 Linux if
the SANs are not SMI-S compliant.
Stretch Cluster Cluster of Clusters