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

See the pfto(7) man page.
VxVM uses this mechanism in its Powerfail Timeout (PFTO) feature. You can
specify a timeout value for individual VxVM disks using the vxdisk command. If
the PFTO setting for a disk I/O is enabled, the underlying driver returns an error
without retrying the I/O if the disk timer (PFTO) expires and the I/O does not
return from the disk.
You can set the PFTO values on a disk or set of disks within a disk group using
the command line. PFTO helps in preventing system hangs due to non-responding
disks.
Starting with Storage Foundation release 5.0.1, Powerfail Timeout (PFTO) has the
following default values:
■ Disabled for HP-UX native multi-pathing devices
■ Enabled for the DMP multi-pathing devices.
■ The default PFTO value is 30 seconds.
You can change the PFTO settings as required. In some cases, when you upgrade
Storage Foundation, the upgrade process resets the PFTO settings for existing
devices to the default values. For information about how PFTO settings are handled
during various upgrade cases, see the Storage Foundation High Availability
Installation Guide.
To set PFTO value on a disk, use the following command:
$ vxdisk -g dg_name set disk_name pfto=value
For example, to set the PFTO value of 50sec on the disk c5t0d6:
$ vxdisk -g testdg set c5t0d6 pfto=50
To set the PFTO on a disk group, use the following command:
$ vxpfto -g dg_name -t 50
For example, to set the PFTO on all disks in the diskgroup testdg:
$ vxpfto -g testdg -t 50
To show the PFTO value and whether PFTO is enabled or disabled for a disk, use
one of the following commands:
$ vxprint -g <dg_name> -l <disk_name>
$ vxdisk -g <dg_name> list <disk_name>
Administering disks
Controlling Powerfail Timeout
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