HP Serviceguard Extended Distance Cluster for Linux A.01.01 Deployment Guide, Third Edition, May 2008

Disaster Tolerance and Recovery in a Serviceguard Cluster
Understanding Types of Disaster Tolerant Clusters
Chapter 130
Key
Limitation
No ability to check the
state of the data before
starting up the
application. If the
volume group (vg) can
be activated, the
application will be
started. If mirrors are
split or multiple paths
to storage are down, as
long as the vg can be
activated, the
application will be
started.
Data resynchronization
does not have a big
impact on system
performance. However,
the performance varies
depending on the
number of times data
resynchronization
occurs. In the case of
MD, data
resynchronization is
done one disk at a time,
using about 10% of the
available CPU time
and taking longer to
resynchronize multiple
LUNs. The amount of
CPU time used is a
configurable MD
parameter.
Specialized storage
required. Currently, XP
with Continuous Access,
and EVA with
Continuous Access are
supported.
No automatic failover
between clusters.
Table 1-1 Comparison of Disaster Tolerant Cluster Solutions (Continued)
Attributes
Extended Distance
Cluster
CLX
Continentalclusters
(HP-UX only)