Managing HP Serviceguard A.11.20.10 for Linux, December 2012

NOTE: CONFIGURED_IO_TIMEOUT_EXTENSION
is supported only with iFCP switches that allow you to
get their R_A_TOV value.
• For switches and routers connecting an NFS server and
cluster-node clients that can run packages using the
NFS-mounted file system; see “Planning for
NFS-mounted File Systems” (page 101).
To set the value for the
CONFIGURED_IO_TIMEOUT_EXTENSION, you must
first determine the Maximum Bridge Transit Delay
(MBTD) for each switch and router. The value should
be in the vendors' documentation. Set the
CONFIGURED_IO_TIMEOUT_EXTENSION to the sum
of the values for the switches and routers. If there is
more than one possible path between the NFS server
and the cluster nodes, sum the values for each path
and use the largest number.
CAUTION: Serviceguard supports NFS-mounted file
systems only over switches and routers that support
MBTD. If you are using NFS-mounted file systems, you
must set CONFIGURED_IO_TIMEOUT_EXTENSION as
described here.
For a fuller discussion of MBTD, see the white paper
Support for NFS as a filesystem type with HP
Serviceguard A.11.20 on HP-UX and Linux available
at http://www.hp.com/go/hpux-serviceguard-docs.
• For clusters in which both of the above conditions
apply.
In this case, set the
CONFIGURED_IO_TIMEOUT_EXTENSION to the higher
of the two values you get from following the instructions
in the preceding two bullets.
Default is 0. The value can range from zero to
2147483647.
SUBNET IP address of a cluster subnet for which IP Monitoring can
be turned on or off (see IP_MONITOR). The subnet must be
configured into the cluster, via NETWORK_INTERFACE and
either HEARTBEAT_IP or STATIONARY_IP. All entries for
IP_MONITOR and POLLING_TARGET apply to this subnet
until the next SUBNET entry; SUBNET must be the first of
each trio.
By default, each of the cluster subnets is listed under
SUBNET, and, if at least one gateway is detected for that
subnet, IP_MONITOR is set to ON and POLLING_TARGET
entries are populated with the gateway addresses, enabling
target polling; otherwise the subnet is listed with
IP_MONITOR set to OFF.
4.7 Cluster Configuration Planning 97