Managing HP Serviceguard A.11.20.20 for Linux, March 2014

Table 5 Failure Recovery Detection Times for an IP Monitored
Ethernet Interface
Failure/Recovery Detection Times (in seconds)
Values of
Network Polling
Interval (NPI) (in
seconds)
~ NPI x 8 - NPI x 91
~ NPI x 4 - NPI x 52
~ NPI x 3 - NPI x 43
~ NPI x 2 - NPI x 34 to 8
~ NPI x 1- NPI x 2>=8
IMPORTANT: HP strongly recommends using the default.
Changing this value can affect how quickly the link-level
and IP-level monitors detect a network failure. See
“Monitoring LAN Interfaces and Detecting Failure: Link Level”
(page 66).
Can be changed while the cluster is running.
CONFIGURED_IO_TIMEOUT_EXTENSION The number of microseconds by which to increase the time
Serviceguard waits after detecting a node failure, so as to
ensure that all pending I/O on the failed node has ceased.
This parameter must be set in the following cases.
• For extended-distance clusters using software mirroring
across data centers over links between iFCP switches;
it must be set to the switches' maximum R_A_TOV value.
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 106).
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.
4.7 Cluster Configuration Planning 101