Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

The above command configures the default behavior, corresponding to
recoveryoption=nothrottle. The above command also configures the default
behavior for the response to I/O failures.
See “Configuring the response to I/O failures” on page 189.
Note: The I/O throttling settings are persistent across reboots of the system.
Configuring Subpaths Failover Groups (SFG)
The Subpaths Failover Groups (SFG) feature can be turned on or off using the
tunable dmp_sfg_threshold.
To turn off the feature, set the tunable dmp_sfg_threshold value to 0:
# vxdmpadm settune dmp_sfg_threshold=0
To turn on the feature, set the dmp_sfg_threshold value to the required number
of path failures which triggers SFG. The default is 1.
# vxdmpadm settune dmp_sfg_threshold=N
The default value of the tunable is “1” which represents that the feature is on.
To see the Subpaths Failover Groups ID, use the following command:
# vxdmpadm getportids {ctlr=ctlr_name | dmpnodename=dmp_device_name \
| enclosure=enclr_name | path=path_name}
Configuring Low Impact Path Probing
The Low Impact Path Probing (LIPP) feature can be turned on or off using the
vxdmpadm settune command:
# vxdmpadm settune dmp_low_impact_probe=[on|off]
Path probing will be optimized by probing a subset of paths connected to same
HBA and array port. The size of the subset of paths can be controlled by the
dmp_probe_threshold tunable. The default value is set to 5.
# vxdmpadm settune dmp_probe_threshold=N
Displaying recovery option values
To display the current settings for handling I/O request failures that are applied
to the paths to an enclosure, array name or array type, use the following command:
Administering Dynamic Multi-Pathing
Administering DMP using vxdmpadm
192