HP XP Cluster Extension Software Administrator Guide

resynchronize. If this is the case, clxrun may take some time to complete. Do not stop
clxrun; use it to check the status of the associated RAID Manager device/copy groups.
Even if the RAID Manager version and the array firmware version allow a delta
resynchronization, the amount of delta data to be transferred between the primary and the
secondary could be long enough for the copy process to take a while.
• If running in fence level ASYNC, the default value of the AsyncTakeoverTimeout is set to a
very high number. This is done because the takeover process for fence level ASYNC can take
much longer when slow communications links are in place; adjust this value after measuring
the Continuous Access Software environment. See “AsyncTakeoverTimeout” (page 52) for
more details.
To prevent premature termination of the takeover commands by the takeover timeout, measure
the time to copy the installed XP disk array cache and adjust the resource online timeout
interval according to the measured copy time. Use only the slowest link Continuous Access
Software link to measure the copy time. This ensures that the disk array cache can be transferred
from the remote disk array, even in the event of a single surviving replication link between the
disk arrays.
In general, because the failover environment is dispersed into two (or more) data centers, the
failover time cannot be expected to be the same as it would be in a single data center with a single
shared disk device.
Restrictions for customized XP Cluster Extension implementations
The following are some restrictions that apply when using the XP Cluster Extension CLI:
• The XP Cluster Extension CLI call clxrun must be invoked before the associated disk resources
are activated.
• Associated disk resources must not be activated on any other system. If other disk resources
are activated, XP Cluster Extension may remove write-access rights for those disk devices
(putting them in read-only mode).
Creating and configuring the user configuration file
The CLI expects as an argument the name configured as the APPLICATION tag value. You do not
need to specify the SearchObject object.
The following is an example of a customized user configuration file when using clxrun:
# This is the XP Cluster Extension User Configuration File (UCF.cfg).
# The COMMON tag specifies the configuration for the
# XP Cluster Extension core environment
#
COMMON
LogLevel info #show disk state info in the logs
# The APPLICATION tag specifies the configuration for the
# XP Cluster Extension failover behavior
APPLICATION sap #the application service
DeviceGroup sapdg #RM dev group for the app service
RaidManagerInstances 22 90 #RM instance number for dev group
XPSerialNumbers 34001 34005 #local and remote array Serial Numbers
DC_A_Hosts eserv1 eserv2 #data center A hostnames
DC_B_Hosts eserv3 eserv4 #data center B hostnames
FenceLevel data #FenceLevel changed from default
APPLICATION netscape #the application service
DeviceGroup netscapedg #RM dev group for the app service
RaidManagerInstances 22 90 #RM instance number for dev group
XPSerialNumbers 34001 34005 #local and remote array Serial Numbers
DC_A_Hosts eserv1 eserv2 #data center A hostnames
DC_B_Hosts eserv3 eserv4 #data center B hostnames
40 XP Cluster Extension and CLI