Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

The default value of iotimeout is 10 seconds. For some applications, such as
Oracle, it may be desirable to set iotimeout to a larger value, such as 60 seconds.
Note: The fixedretry and timebound settings are mutually exclusive.
The following example configures time-bound recovery for the enclosure enc0,
and sets the value of iotimeout to 60 seconds:
# vxdmpadm setattr enclosure enc0 recoveryoption=timebound \
iotimeout=60
The next example sets a fixed-retry limit of 10 for the paths to all Active/Active
arrays:
# vxdmpadm setattr arraytype A/A recoveryoption=fixedretry \
retrycount=10
Specifying recoveryoption=default resets DMP to the default settings
corresponding to recoveryoption=fixedretry retrycount=5, for example:
# vxdmpadm setattr arraytype A/A recoveryoption=default
The above command also has the effect of configuring I/O throttling with the
default settings.
See “Configuring the I/O throttling mechanism” on page 186.
Note: The response to I/O failure settings is persistent across reboots of the system.
Configuring the I/O throttling mechanism
By default, DMP is configured with I/O throttling turned off for all paths. To
display the current settings for I/O throttling that are applied to the paths to an
enclosure, array name or array type, use the vxdmpadm getattr command.
See “Displaying recovery option values” on page 188.
If enabled, I/O throttling imposes a small overhead on CPU and memory usage
because of the activity of the statistics-gathering daemon. If I/O throttling is
disabled, the daemon no longer collects statistics, and remains inactive until I/O
throttling is re-enabled.
To turn off I/O throttling, use the following form of the vxdmpadm setattr
command:
Administering Dynamic Multipathing
Administering DMP using vxdmpadm
186