HP StorageWorks Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide (AA-RPHZF-TE, March 2004)

Configuring the Optional Advanced DRM Solutions
160 Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide
Figure 25: Bidirectional DRM configuration
Stretched Cluster DRM Solution
DRM supports Microsoft Cluster Servers (MSCS) running Windows 2000/NT. The term
stretched cluster means that half of the cluster is at the primary site, and the other half is at the
alternate site. If the primary server fails, MSCS fails over the application to the surviving
server at the alternate site and resumes operations using the primary site storage.
Applications running in a stretched cluster in failover mode incur a performance penalty
because of the time that it takes to read or write data across the intersite link (ISL). The
performance penalty is directly proportional to the distance between the two sites—the greater
the distance, the greater the penalty. However, at separation distances of up to 100 km, you
should see no additional performance degradation.
For more information on stretched cluster support, go to the HP ProLiant HA/F500 website at:
http://h18000.www1.hp.com/solutions/enterprise/highavailability/microsoft/haf500/
index-ma8000.html
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