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

The value of the argument to retrycount specifies the number of retries to be
attempted before DMP reschedules the I/O request on another available path, or
fails the request altogether.
As an alternative to specifying a fixed number of retries, you can specify the
amount of time DMP allows for handling an I/O request. If the I/O request does
not succeed within that time, DMP fails the I/O request. To specify an iotimeout
value, use the following command:
# vxdmpadm setattr \
{enclosure enc-name|arrayname name|arraytype type} \
recoveryoption=timebound iotimeout=seconds
The default value of iotimeout is 300 seconds. For some applications such as
Oracle, it may be desirable to set iotimeout to a larger value. The iotimeout value
for DMP should be greater than the I/O service time of the underlying operating
system layers.
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 360 seconds:
# vxdmpadm setattr enclosure enc0 recoveryoption=timebound \
iotimeout=360
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 191.
Note: The response to I/O failure settings is persistent across reboots of the system.
Administering Dynamic Multi-Pathing
Administering DMP using vxdmpadm
190