Understanding and Designing Serviceguard Disaster Recovery Architectures

Table 6 Comparison of disaster recovery Cluster Solutions (continued)
ContinentalclustersMetroclusterExtended Distance Cluster
for RAC (HP-UX only)
Extended Distance ClusterAttributes
You must reconnect
after the application is
Client detects the lost
connection. You must
Client may already have
a standby connection to
remote site.
Client detects the lost
connection. You must
reconnect after the
Client
Transparency
recovered at second
site.
reconnect once the
application isapplication is recovered at
second site. recovered at second
site.
Based on the limit of
the number of nodes
3 to 16 nodes* 2 nodes with SLVM or
CVM with a maximum
On HP-UX:
2 to 16 nodes (up to four
when using dual lock disks)
Maximum
Cluster Size
Allowed per
Serviceguard/SGeRAC
cluster.
distance of 100km. * 2,
4, 6, or 8 nodes to eight
nodes with CVM or CFS
using LVM or VxVM. 2, 4,
6, or 8 nodes (up to four
with a maximum distance
of 10km.
when using dual lock disks)
using CFS.
On Linux:
2 to 16 nodes
Identical storage is
required if
Identical Storage is
required.
Identical storage is not
required (replication is
Identical storage is not
required (replication is
Storage
storage-based
mirroring is used.
host-based with either
*MirrorDisk/UX or CVM
Mirroring).
host-based with either
MirrorDisk/UX or (Veritas)
VxVM in HP-UX and
Identical storage is not
required for other data
Multiple Device (MD) on
Linux).
replication
implementations.
WANDark FiberDark FiberDark FiberData
Replication
Link
LAN
Dark Fiber
(pre-integrated
solution)
Continuous Access over
IP
Continuous Access over
ATM
Continuous Access
over IP (pre-integrated
solution)
Continuous Access
over ATM
(pre-integrated
solution)
Two configurations:Single IP Subnet
(requires a common
Single IP subnetCross Subnet for all cluster
notes if the Cross Subnet
Cluster
Network
Single IP subnet for
both clusters (LAN
subnet for all cluster
nodes), except for
Cross-Subnet clusters.
feature is not used or not
available.
¹ Serviceguard versions
supporting the Cross
connection between
clusters)
Two IP subnets – one
per cluster (WAN
Subnet feature do not
require a common subnet
for all cluster nodes.
connection between
clusters)
Serviceguard+On HP-UX:Serviceguard+Serviceguard (no other
clustering SW is required).
Disaster
recovery
Continentalclusters +Serviceguard+SGeRAC
Solutions
(Metrocluster
Continuous Access XP
or
Metrocluster with
Continuous Access for
P9000 and XP
Software
Licenses
Required
Metrocluster
Continuous Access
EVA
or
Metrocluster Continuous
Access EVA
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