Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Physical Data Replication for ContinentalClusters Using Continuous Access XP
Maintaining the Continuous Access XP Data Replication Environment
Chapter 6324
NOTE Long delays in package startup time will occur in those situations
when recovering from broken pair affinity.
• The value of RUN_SCRIPT_TIMEOUT in the package ASCII file should
be set to NO_TIMEOUT or to a large enough value to take into
consideration the extra startup time due to getting status from the
XP disk array. See the previous paragraph for more information on
the extra startup time.
• Online cluster configuration changes may require a Raid Manager
configuration file to be changed. Whenever the configuration file is
changed, the Raid Manager instance must be stopped and restarted.
The Raid Manager instance must be running before any
ContinentalClusters package movement occurs.
• A given file system must not reside on more than one XP frame for
either the PVOL or the SVOL. A given LVM Logical Volume (LV)
must not reside on more than one XP frame for either the PVOL or
the SVOL.
• The application is responsible for data integrity, and must use the
O_SYNC flag when ordering of I/Os is important. Most relational
database products are examples of applications that ensure data
integrity by using the O_SYNC flag.
• Each host must be connected to only the XP disk array that contains
either the PVOL or the SVOL. A given host must not be connected to
both the PVOL and the SVOL of a continuous access pair.