Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

151Administering dynamic multipathing (DMP)
Administering DMP using vxdmpadm
Specifying recoveryoption=default resets I/O throttling to the default settings
corresponding to
recoveryoption=throttle queuedepth=20, for example:
# vxdmpadm setattr arraytype A/A recoveryoption=default
This command also has the effect of configuring a fixed-retry limit of 5 on the paths. See
“Configuring the response to I/O failures” on page 148 for details.
Note: The I/O throttling settings are persistent across reboots of the system.
Displaying recoveryoption values
The following example shows the vxdmpadm getattr command being used to display the
recoveryoption option values that are set on an enclosure.
# vxdmpadm getattr enclosure HDS9500-ALUA0 recoveryoption
ENCLR-NAME RECOVERY-OPTION DEFAULT[VAL] CURRENT[VAL]
===============================================================
HDS9500-ALUA0 Throttle Timebound[10] Queuedepth[60]
HDS9500-ALUA0 Error-Retry Fixed-Retry[5] Timebound[20]
This shows the default and current policy options and their values. The possible option
settings are summarized in the following table.
Recovery option Possible settings Description
Error-Retry settings:
recoveryoption=fixedretry
recoveryoption=timebound
Fixed-Retry (retrycount)
Timebound (iotimeout)
DMP retries a failed I/O request
for the specified number of
times if I/O fails.
DMP retries a failed I/O request
after the specified time in
seconds if I/O fails.
Throttle settings:
recoveryoption=nothrottle
recoveryoption=throttle
None
Queuedepth (queuedepth)
Timebound (iotimeout)
Not applicable
DMP throttles the path if the
specified number of queued I/O
requests is exceeded.
DMP throttles the path if an I/O
request does not return within
the specified time in seconds.